*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19840
19850
19861
19870
19885
19890
19900
19913
19921
19934
19940
19954
19966
19975
199811
19993
20005
20014
20020
20032
20040
20052
20060
20071
20080
20090
20100
20111
20120
20130
20140
20150
20160
20170
Total59