*Excludes Observations that spanned multiple years

Pre 19704
19700
19710
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19830
19841
19850
19860
19871
19880
19891
19900
19910
19921
19931
19940
19950
19960
19972
19980
19990
20000
20010
20020
20032
20041
20051
20060
20071
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total17