*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19792
19800
19810
19820
19830
19841
19850
19867
19876
19881
19894
19901
19913
19929
199325
19946
199514
19961
19973
19982
19994
20002
20011
20025
20030
20040
200510
20061
20070
20081
20090
201030
201136
20124
201311
20149
20150
20160
20171
Total200