*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
19871
19880
19890
19900
19913
19921
19931
19942
19950
19960
19970
19983
19993
20000
20010
20024
20030
20040
20051
20062
20072
20081
20090
20100
20110
20120
20130
20140
20150
20160
20170
20180
20190
20200
20210
20220
20230
Total24