*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
19871
19883
19890
19903
19910
19921
19932
19941
19952
19962
19974
19981
19991
20002
20011
20022
20031
20040
20054
20060
20070
20081
20090
20106
20113
20120
20130
20140
20150
20160
20170
Total41