*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19841
19852
19860
19870
19880
19890
19901
19910
19921
19930
19940
19950
19961
19970
19980
19990
20000
20010
20020
20030
20040
20050
20060
20070
20081
20090
20102
20110
20121
20131
20141
20151
20160
20171
20181
20190
20200
20210
Total16