条形图按组平均线

Question

我正在为每个群集设置一个栏。我需要每个条形的高度为每个邮政编码中的平均值（基于人口）。然后，我想要所有拉链的平均值的水平虚线。

    ## Data
df <- data.frame(
zipcode=c("10001","10002","10003","10004","10005","10006","10007","10008","10009","10010"),
 black= c(2,3,4,6,7,8,9,11,13,15),
 white = c(6,8,12,14,15,16,14,14,14,22),
 population = c(11,22,33,44,55,66,77,88,99,100),
 female = c(5,11,32,22,31,21,44,11,22,14),
cluster = c("1","2","3","2","2","1","3","3","3","1"))
print(df)

> print(df)
   zipcode black white population female cluster
1    10001     2     6         11      5       1
2    10002     3     8         22     11       2
3    10003     4    12         33     32       3
4    10004     6    14         44     22       2
5    10005     7    15         55     31       2
6    10006     8    16         66     21       1
7    10007     9    14         77     44       3
8    10008    11    14         88     11       3
9    10009    13    14         99     22       3
10   10010    15    22        100     14       1

如果我尝试按％white制作群集的条形图。 白人的总体平均值为23％，这是一条水平虚线。

类别1的总体平均白人为24％ 群集2的总体平均白人为30.5％ 第3组的整体白人平均水平为18％