*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19811
19821
19830
19840
19852
19860
19872
198810
19890
19902
19910
19923
19930
19944
19951
19960
19970
19981
19994
20000
20011
20020
20035
20040
20051
20060
20070
20080
20090
20100
20110
20121
20130
20140
20151
20160
20170
20180
20190
20200
20210
20220
Total40