*Excludes Observations that spanned multiple years

Pre 19700
19700
19711
197275
197329
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
198421
19850
19861
19870
198838
19891
19908
199121
19925
199314
19949
19950
19960
19973
19980
199911
20005
20011
20022
20030
20041
20050
20060
20070
20080
20090
20100
20110
20120
20130
20140
20150
20160
20171
20180
20190
Total248