*Excludes Observations that spanned multiple years

Pre 19700
19701
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19901
19917
19920
19938
19945
19950
19965
19971
19980
19990
20000
20013
20020
20031
20044
20056
20060
20070
20081
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total43