*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19881
19891
19900
19910
19920
19930
19940
19951
19960
19970
19980
19990
20000
20012
20023
20030
20040
20050
20061
20071
20081
20091
201016
201111
20121
20132
20143
20151
20163
20171
20180
Total50