*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19821
19837
19840
19851
19860
198712
19882
19893
19900
19910
19921
19930
19942
19954
19960
19972
19981
19993
20008
20010
20020
20031
20040
20050
20060
20078
20086
20094
20104
20111
20120
20130
20140
20150
20160
20170
Total71