*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19742
19752
19760
19770
19780
19790
19800
19810
19821
19831
19841
19850
19861
19870
19880
19890
19900
19913
19921
19930
19942
19950
19960
19970
19980
19990
20001
20010
20020
20030
20040
20050
20060
20070
20081
20090
20100
20111
20120
20130
20141
20150
20160
20171
20181
20190
20200
Total20