*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19821
19830
19842
19854
19860
19870
19882
19890
19900
19910
19920
19931
19946
19953
19961
19975
19980
19990
20000
20011
20020
20034
20040
20050
20062
20078
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total40