*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19840
19851
19860
19870
19880
19890
19901
19913
19921
19933
19949
19952
19968
19976
19981
19990
20002
20010
20027
200314
20040
20051
20062
20070
20085
20092
20101
20111
20120
20130
20140
20151
20162
20170
20187
Total81