*Excludes Observations that spanned multiple years

Pre 19701
19700
19711
19721
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19841
19851
19860
19871
19880
19892
19901
19913
19920
19932
19947
19951
19960
19972
19981
19993
20000
20012
20020
20030
20040
20052
20060
20072
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total34