*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19781
19790
19801
19810
19820
19832
19841
19851
19861
19871
19880
198912
19900
19915
19927
19930
19941
19950
19961
19971
19980
19991
20000
20011
20020
20033
20040
20050
20060
20070
20089
20090
20100
20110
20120
20130
20141
20150
20160
20170
Total50