*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19841
19850
19860
19870
19881
19891
19900
19911
19921
19930
19940
19952
19960
19970
19980
19990
20000
20011
20020
20030
20040
20050
20067
20076
20083
20090
20100
20111
20120
20130
20140
20150
20160
20170
Total25