*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19731
19740
19750
19760
19770
19780
19790
19801
19810
19821
19830
19841
19850
19863
19870
19880
198910
19901
199160
19920
19930
19940
19952
19961
19970
19980
19990
20000
20010
20020
20030
20040
20050
20060
20070
20082
20093
20101
20112
20120
20130
20140
20150
20160
20170
Total89