*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19840
19850
19860
19870
19880
19891
19906
19917
19922
19939
19941
19954
19965
19970
19980
19990
20000
20011
20020
20030
20040
20050
20060
20070
20088
20090
20109
20117
20120
20130
20141
20150
20161
20170
Total63