*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
198616
19870
19880
19897
19900
19910
19920
19931
19940
199512
19960
19975
19981
19992
20000
20016
20021
20030
20040
20058
20061
20070
20084
20090
201013
201117
20120
20130
20140
20150
20160
20170
Total95