*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19722
19731
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19846
19850
19860
19877
198865
19891
19904
199194
199226
199330
19941
19956
19960
19973
19980
19991
20002
20010
20021
20032
20040
20050
20060
20070
20081
20090
20104
20112
20121
20130
20140
20150
20161
20171
20180
Total263