*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19862
19870
19880
19891
199012
19910
19920
19931
19941
19950
19961
19972
19980
19990
20000
20010
20023
20031
20040
20051
20060
20070
20088
20090
20100
20113
20120
20132
20141
20150
20165
20170
Total44