*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
198713
198833
19892
199017
199128
19921
19931
19942
19952
19960
19970
19980
19990
20000
20010
20020
20031
20041
20050
20060
20070
20080
20090
20100
20111
20121
20132
20140
20150
20161
20171
20182
20193
20200
20210
20220
Total112