我有一个数据集，其中包含73个站点的位置信息（纬度，长度）和年度贡献。这是数据集的片段 -
Station Year Contribution Lat Long
1 USC00020750 1964 6.381039 36.6778 -110.5411
2 USC00020750 1965 10.638735 36.6778 -110.5411
3 USC00020750 1966 5.568942 36.6778 -110.5411
4 USC00020750 1967 8.214286 36.6778 -110.5411
5 USC00020750 1968 13.981570 36.6778 -110.5411
6 USC00020750 1969 8.607199 36.6778 -110.5411
7 USC00020750 1970 12.183436 36.6778 -110.5411
8 USC00020750 1971 11.382114 36.6778 -110.5411
9 USC00020750 1972 6.647583 36.6778 -110.5411
10 USC00020750 1973 4.921077 36.6778 -110.5411
11 USC00020750 1974 13.102512 36.6778 -110.5411
12 USC00020750 1975 14.181487 36.6778 -110.5411
13 USC00020750 1976 7.141769 36.6778 -110.5411
14 USC00020750 1977 7.267267 36.6778 -110.5411
15 USC00020750 1978 10.701754 36.6778 -110.5411
16 USC00020750 1979 14.981949 36.6778 -110.5411
17 USC00020750 1980 14.671654 36.6778 -110.5411
18 USC00020750 1981 6.272401 36.6778 -110.5411
19 USC00020750 1982 6.117234 36.6778 -110.5411
20 USC00020750 1983 6.985224 36.6778 -110.5411
...
Station Year Contribution Lat Long
3630 USW00093129 1993 16.330451 37.7086 -113.0944
3631 USW00093129 1994 15.115512 37.7086 -113.0944
3632 USW00093129 1995 8.773946 37.7086 -113.0944
3633 USW00093129 1996 8.362573 37.7086 -113.0944
3634 USW00093129 1997 7.858156 37.7086 -113.0944
3635 USW00093129 1998 7.174763 37.7086 -113.0944
3636 USW00093129 1999 6.158664 37.7086 -113.0944
3637 USW00093129 2000 18.498896 37.7086 -113.0944
3638 USW00093129 2001 12.168397 37.7086 -113.0944
3639 USW00093129 2002 7.325103 37.7086 -113.0944
3640 USW00093129 2003 10.321489 37.7086 -113.0944
3641 USW00093129 2004 7.204181 37.7086 -113.0944
3642 USW00093129 2005 11.059623 37.7086 -113.0944
3643 USW00093129 2006 8.206687 37.7086 -113.0944
3644 USW00093129 2007 7.790078 37.7086 -113.0944
3645 USW00093129 2008 12.083333 37.7086 -113.0944
3646 USW00093129 2009 7.763713 37.7086 -113.0944
3647 USW00093129 2010 11.049468 37.7086 -113.0944
3648 USW00093129 2011 7.131333 37.7086 -113.0944
3649 USW00093129 2012 5.926401 37.7086 -113.0944
3650 USW00093129 2013 9.509202 37.7086 -113.0944
我想在空间地图上为一组电台（让我们说3）制作年度贡献（boxplot(Contribution~Year,data=data)）的箱线图。我知道在一个图形（Plot multiple boxplot in one graph）中绘制多个箱图的方法，但我不确定如何在地图上显示它们。任何帮助将不胜感激。