*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19865
19870
19880
19895
19901
19910
19920
19931
19946
19950
19961
19970
19980
19990
20002
20013
20021
20030
20040
200517
20061
20071
20081
20091
20100
20110
20120
20130
20140
20150
20160
20170
Total46