*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19910
19920
19931
19940
19950
19960
19971
19981
19990
20001
20010
20020
20031
20041
20050
20060
20070
20081
20090
20100
20110
20120
20130
20141
20150
20160
20173
20180
20190
20200
20210
20220
20230
20240
Total12