*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19831
19840
19850
19860
19870
19880
19890
19900
19913
19920
19932
19940
199537
19960
19973
19980
19990
20000
20010
20020
20030
20040
20051
20062
20070
20085
20092
20100
20110
20120
20132
20140
20151
20163
201722
201825
201927
20200
Total137