*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
19880
19890
19900
19910
19922
19930
19942
19956
19960
19971
19984
19992
20000
20015
20020
20031
20045
20052
20064
20070
20082
20091
20100
20110
20120
20130
20140
20150
20160
20170
Total38