R：每年获取一列以获取面板数据

Question

我想赢得“返回”列。但是，我想每年赢得胜利。 我的数据看起来像这样：

structure(list(Name = c("A", "A", "A", "A", "A", "A", "B", "B", 
"B", "B", "B", "B", "C", "C", "C", "C", "C", "C"), Date = c("01.09.2018", 
"02.09.2018", "03.09.2018", "05.11.2021", "06.11.2021", "07.11.2021", 
"01.09.2018", "02.09.2018", "03.09.2018", "05.11.2021", "06.11.2021", 
"07.11.2021", "01.09.2018", "02.09.2018", "03.09.2018", "05.11.2021", 
"06.11.2021", "07.11.2021"), Return = c(0.05, 0.1, 0.8, 1.5, 
0.1, -2, 0.4, 0.6, 0.6, 0.2, -0.5, -0.9, -0.4, 1.7, 0.3, -4, 
0.6, 0.5), Year = c("2018", "2018", "2018", "2021", "2021", "2021", 
"2018", "2018", "2018", "2021", "2021", "2021", "2018", "2018", 
"2018", "2021", "2021", "2021")), row.names = c(NA, -18L), class = c("grouped_df", 
"tbl_df", "tbl", "data.frame"), groups = structure(list(Year = c("2018", 
"2021"), .rows = structure(list(c(1L, 2L, 3L, 7L, 8L, 9L, 13L, 
14L, 15L), c(4L, 5L, 6L, 10L, 11L, 12L, 16L, 17L, 18L)), ptype = integer(0), class = c("vctrs_list_of", 
"vctrs_vctr", "list"))), class = c("tbl_df", "tbl", "data.frame"
), row.names = c(NA, -2L), .drop = TRUE))

我尝试了以下代码也有效：

Data <- Data %>%
  group_by(Year) %>%
  mutate("Winsorized Return" = Winsorize(`Return`, probs=c(0.01, 0.99)))

现在我执行了相同的操作，但每年没有对数据进行分组：

Data <- Data %>%
  mutate("Winsorized Return" = Winsorize(`Return`, probs=c(0.01, 0.99)))

即使我在第一个代码中使用了“ group_by（年），我也得到了完全相同的结果。 有人可以向我解释为什么结果是一样的吗？即使我对我的真实（非常大）数据集进行了同样的事情，也会得到相同的结果。
我是否必须使用另一个代码才能每年获取“返回”列？

非常感谢您的任何帮助！