*Excludes Observations that spanned multiple years

Pre 197017
19700
19711
19721
19730
19740
19750
19760
19771
19780
19790
19800
19810
19820
19830
19841
19851
19860
19870
19880
19890
19900
19913
19920
19933
19940
19950
19960
19970
19980
19990
20005
20010
20020
20030
20040
20050
20061
20070
20080
20090
20100
20111
20120
20130
20141
20151
20160
20170
20180
20190
Total37