*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19731
19740
19750
19760
19770
19780
19790
19801
19810
19821
19830
19842
19850
19860
19870
19881
19891
199011
199123
199220
199320
199410
19953
19961
19971
19980
19990
20000
20010
20020
20030
20040
20050
20060
20070
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total96