*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19771
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19888
19890
19902
19918
199210
199312
19946
19951
19965
19970
19984
19990
20002
20010
20020
20030
20040
20051
20061
20070
200820
20098
20102
20111
20120
20130
20141
20151
20161
20170
20182
20192
20200
20210
20220
Total99