*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19866
19876
19880
19892
19901
19910
19924
19933
19941
199515
19960
19974
19980
19990
20000
20013
20022
20035
20041
20051
20060
20070
20084
20090
20100
20111
20120
20130
20140
20150
20160
20170
Total59