*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19722
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19842
19850
19860
19872
198817
19890
19904
199145
199211
199322
19941
19956
19960
19972
19980
19994
20002
20016
20021
20030
20040
20050
20060
20071
20085
20090
20102
20113
20120
20130
20141
20150
20160
20170
20181
20190
Total140