*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19751
19760
19770
19780
19790
19800
19810
19821
19830
19840
19852
19860
19870
19881
19890
19900
19912
19920
19930
19940
19953
19960
19970
19980
19990
20000
20011
20020
20030
20040
20052
20060
20070
20080
20090
20102
20111
20120
20130
20141
20151
20161
20170
20180
20192
20200
20210
20220
Total21