*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19832
19841
19850
19861
19871
19880
19890
19900
19911
19920
19932
19941
19951
19960
19970
19981
19990
20000
20010
20020
20039
20041
20050
20060
20070
20084
20090
20100
20110
20120
20130
20140
20150
20161
20170
Total27