*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
197221
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19859
19860
19870
19882
19890
19902
19912
199230
19933
19941
19950
19960
19970
19981
19990
20005
20010
20020
20030
20040
20050
20060
20070
20081
20090
20100
20114
20120
20130
20140
20150
20161
20170
20180
Total82