*Excludes Observations that spanned multiple years

Pre 19704
19700
19710
19720
19730
19740
19751
19760
19770
19780
19790
19800
19811
19820
19830
19841
19850
19861
19870
19880
19890
19900
19910
19920
19930
19940
19951
19960
19970
19980
19990
20000
20010
20020
20031
20040
20050
20061
20070
20081
20090
20100
20110
20120
20130
20140
20151
20160
20170
Total13