*Excludes Observations that spanned multiple years

Pre 197013
19701
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19821
19830
19841
19850
19863
19879
19881
19891
19903
19910
19921
19933
19942
19952
199613
199712
19984
19991
200010
20010
20025
200312
20040
20051
20060
20072
20081
20090
20100
20110
201217
20130
20141
20150
20160
20170
Total120