*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
19880
19895
19900
19910
19921
19933
19940
19955
19960
19970
19980
19990
20000
20016
20020
20030
200444
20050
20060
20070
20089
20090
201028
201143
20120
20130
20140
20150
20160
20171
Total145