*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19885
19890
19903
19910
19921
19930
19940
19950
19961
19971
19982
19990
20001
20011
20021
20031
20040
20051
20060
200712
20080
200910
20104
20111
20120
20130
20140
20150
20160
20170
Total45