*Excludes Observations that spanned multiple years

Pre 19705
19700
19710
19720
19730
19740
19750
19760
19771
19780
19790
19802
19812
19820
19830
19840
19850
19860
19870
19880
19891
19900
19912
19920
19938
19940
19950
19962
19971
19981
19990
20003
20010
20020
20030
20040
20050
20061
20070
20081
20090
20100
20111
20121
20130
20140
20150
20160
20170
20180
Total32