*Excludes Observations that spanned multiple years

Pre 19706
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19835
19841
19850
19860
19872
19880
19890
19901
19912
19920
19934
19946
199522
19960
19971
19980
19990
20000
20011
20020
20030
20041
20050
20060
20070
20080
20090
20100
20110
20120
20130
20140
20150
20162
20170
Total54