*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19721
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19883
19891
199033
199111
199215
19931
19940
19950
19960
19977
19980
19990
20001
20011
20020
20030
20040
20050
20060
20070
20081
20090
201036
20114
20125
20137
20143
20151
20167
20170
201815
20190
Total153