*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19781
19790
19800
19810
19820
19830
19840
19851
19860
19878
19886
19891
19905
19910
19920
19930
19944
19951
19962
199710
19981
19991
20000
20010
20020
20030
20041
20050
20060
20070
20080
20091
20100
20110
20121
20130
20141
20151
20165
20170
20181
20190
20200
Total52