*Excludes Observations that spanned multiple years

Pre 19704
19700
19710
19720
19730
19740
19750
19761
19770
19780
19790
19800
19810
19820
19830
19840
19851
19860
19870
19881
19890
19900
19910
19920
19933
19942
19953
19960
19974
19983
19991
20004
20012
20021
20033
20042
20051
20061
20071
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total38