*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19841
19850
19861
19870
19880
19891
19900
19911
19921
19931
19940
19951
19963
199715
19980
19996
20000
20010
20020
20030
20040
20050
20061
20070
20082
20090
201012
201126
20121
20139
20145
20150
20160
20170
Total87