*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19761
19770
19781
19790
19800
19810
19820
19831
19841
19850
19861
19871
19880
19892
19900
19910
19920
19930
19940
19950
19960
19970
19981
19990
20000
20011
20020
20030
20040
20050
20060
20070
20081
20090
20100
20111
20120
20130
20141
20150
20163
20172
20181
20190
20200
Total19