*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19842
19851
19861
19871
19880
19891
19902
19910
19920
19930
19944
19953
19960
19971
19981
19992
20001
20010
20020
20030
20040
20050
20060
20071
20080
20091
20100
20111
20120
20130
20141
20150
20160
20170
Total24