*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19728
19737
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19866
19870
198847
19897
19906
19918
19921
19932
19941
19952
19960
19971
19982
19990
20001
20010
20020
20030
20040
20050
20061
20070
200810
20091
20105
201128
20124
20130
20140
20152
20162
20171
20180
Total153