angualr页面返回上一页，上一页数据没了。

Question

点击查询，点击选中资料12月份，返回上一页，并不是12月，中间内容清空了。

fastTicket: {                                                                                                                                                                                                            
    url: '/fastTicket',                                                                                                                                                                                                  
    template: __inline('./views/fastTicket.html'),                                                                                                                                                                       
    controller: ["$scope", "$state", "$stateParams", '$rootScope', '$sessionStorage', 'dataHelper', 'tip', '$location', function($scope, $state, $stateParams, $rootScope, $sessionStorage, dataHelper, tip, $location) {
        // var currentYear = new Date().getFullYear();                                                                                                                                                                   
        $scope.currentYear = new Date().getFullYear();                                                                                                                                                                   
        $scope.currentMonth = new Date().getMonth() + 1;                                                                                                                                                                 
                                                                                                                                                                                                                         
        $scope.$on('datePickerInfo', function(event, data) {                                                                                                                                                             
            $scope.currentYear = data.year;                                                                                                                                                                              
            $scope.year = data.year;                                                                                                                                                                                     
            var m = Number(data.month) < 10 ? '0' + data.month : data.month;                                                                                                                                             
            $scope.month = m;                                                                                                                                                                                            
            $scope.currentMonth = m;                                                                                                                                                                                     
            var query = data.year + '-' + m;                                                                                                                                                                             
            dataHelper.monthlyBillsInvoiceList(query).then(function(result) {                                                                                                                                            
                if(result && result.code == 0) {                                                                                                                                                                         
                    if(!result.data.length) {                                                                                                                                                                            
                        tip.warn(1, '没有查询到相关信息');                                                                                                                                                                        
                        $scope.list = {};                                                                                                                                                                                
                        return;                                                                                                                                                                                          
                    }                                                                                                                                                                                                    
                    $scope.list = result.data;                                                                                                                                                                           
                } else {                                                                                                                                                                                                 
                    tip.warn(result.code, result.msg);                                                                                                                                                                   
                }                                                                                                                                                                                                        
            });                                                                                                                                                                                                          
        });                                                                                                                                                                                                              
        $scope.pjx = function(id, status) {                                                                                                                                                                              
            var absUrl = $location.absUrl(),                                                                                                                                                                             
                query = $scope.year + '' + $scope.month;                                                                                                                                                                 
            if($location.search().page) {                                                                                                                                                                                
                var pg = absUrl.replace(/page=(\d+)/, 'page=' + $location.search().page);                                                                                                                                
            } else {                                                                                                                                                                                                     
                var pg = absUrl + "?page=" + query;                                                                                                                                                                      
            }                                                                                                                                                                                                            
            history.pushState({}, "", pg);                                                                                                                                                                               
            $sessionStorage.data = $scope.list;                                                                                                                                                                          
            $state.go('billDetail', {                                                                                                                                                                                    
                id: id,                                                                                                                                                                                                  
                status: status                                                                                                                                                                                           
            });                                                                                                                                                                                                          
        }                                                                                                                                                                                                                
                                                                                                                                                                                                                         
        $scope.$on('pjax', function(event, data) {                                                                                                                                                                       
            if(data == 1) return;                                                                                                                                                                                        
            $scope.currentYear = parseInt(new String(data).substring(0, 4), 10);                                                                                                                                         
            $scope.currentMonth = parseInt(new String(data).substring(4), 10);                                                                                                                                           
            var data = $sessionStorage.data;                                                                                                                                                                             
            $scope.list = data;                                                                                                                                                                                          
        })                                                                                                                                                                                                               
                                                                                                                                                                                                                         
    }]                                                                                                                                                                                                                   
},