*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19861
19870
19881
19890
19900
19911
19921
19930
19941
19950
19960
19972
19980
19990
20000
20011
20020
20030
20040
20050
20062
20070
20085
20090
201055
201146
20120
20131
20141
20152
20161
20170
Total121