*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19731
19740
19750
19760
19770
19781
19790
19800
19810
19820
19830
19840
19850
19860
19871
19880
19890
19901
19910
19920
19931
19941
19951
19960
19971
19981
199910
20000
20011
20020
20031
20040
20050
20060
20070
20080
20090
20108
20113
20120
20130
20140
20152
201631
20171
20180
Total66