*Excludes Observations that spanned multiple years

Pre 19700
19700
19711
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19831
19841
19850
19860
19870
19880
19891
19900
19910
19921
19932
19943
19958
19960
19970
19980
19993
20001
200113
20021
20031
20041
20050
20061
20070
20084
20091
201021
201147
20120
201324
20144
20150
20166
20171
201819
201910
20201
20210
20220
Total178