*Excludes Observations that spanned multiple years

Pre 19700
19700
19711
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19855
19860
19871
19880
19893
19902
1991187
199283
199341
19941
19951
19961
19970
19980
19990
20000
20010
20020
20030
20040
20050
20060
20070
20080
20090
20100
20110
20120
20130
20140
20151
20160
20171
20181
20190
20200
Total329