*Excludes Observations that spanned multiple years

Pre 197021
19700
19711
19721
19730
19740
19752
19760
19772
19780
19790
19800
19812
19822
19830
19841
19850
19860
19870
19880
19890
19903
19911
19920
19930
19947
19950
19960
19971
19980
19990
20001
20010
20020
20030
20040
20051
200613
20077
20082
20091
20100
20111
20120
20130
20140
20150
20160
20170
Total70