*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19841
19850
198611
19870
19880
19891
19903
199123
19922
19930
19942
19956
19960
19973
19980
19993
20000
20010
20027
200312
20042
20054
20060
20072
20084
20090
20100
20110
20120
20130
20140
20150
20162
20170
Total88