*Excludes Observations that spanned multiple years

Pre 19701
19700
19711
19721
19730
19740
19751
19760
19770
19781
19790
19800
19810
19820
19835
19840
19850
19860
19871
19889
19890
19901
19910
19920
19935
19941
19950
19961
19970
19980
19990
20000
20010
20020
20031
20040
20050
20060
20070
20080
20092
20100
20110
20120
20131
20141
20150
20160
20170
Total33