*Excludes Observations that spanned multiple years

Pre 19708
19700
19710
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19830
19841
19850
19860
19872
19880
19891
19900
19910
19920
19930
19940
19950
19961
19970
19980
19990
20000
20010
20020
20030
20041
20050
20060
20070
20080
20091
20100
20111
20120
20130
20141
20150
20160
20170
20180
20190
20200
Total18