*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19722
19731
19740
19750
19760
19770
19780
19790
19800
19810
19822
19837
19841
19855
19860
19873
198824
198919
199012
199170
19926
199339
19941
19956
19960
19970
19982
19993
20002
20013
20029
20031
20041
20056
20062
20070
200810
20090
20102
20114
20120
20130
20140
20150
20161
20170
20180
Total245