*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19781
19790
19800
19810
19821
19830
19840
19851
19860
19870
19880
19890
19900
19910
19923
19936
19942
19953
19960
19976
19980
19990
20000
20012
20020
20033
20044
20050
20060
20070
20084
20090
20100
20110
20120
20130
20140
20150
20161
20170
Total37