*Excludes Observations that spanned multiple years

Pre 19700
19700
19712
19720
19730
19740
19750
19762
19772
19780
19791
19800
19810
19820
19830
19840
19850
19860
19870
19885
19892
19900
19918
19920
19935
19941
19955
19962
19970
19983
19990
20001
200111
20025
20030
20041
20050
20060
20070
20080
20090
20101
20111
20120
20130
20142
20150
20160
20170
20180
20190
20200
Total60