*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19834
19840
19851
19860
19870
19880
19890
19901
19911
19926
19931
19940
199510
19960
19979
19981
19990
20000
20010
20020
20033
20040
20051
20061
20070
200818
20090
20104
201116
20121
20132
20140
20150
20160
20170
Total80