*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19821
19830
19845
19851
19862
19870
19881
198929
19902
19914
19927
19930
19949
19955
19966
19975
19981
19990
20000
20012
20020
20034
20041
20052
200610
20075
20081
20091
20101
20115
20120
20130
20140
20150
20160
20170
Total110