*Excludes Observations that spanned multiple years

Pre 19700
19700
19712
19725
19730
19740
19750
19760
19770
19780
19791
19800
19811
19820
19831
19840
19850
19860
19870
198885
19890
199014
199116
19929
199335
19942
199525
19969
19977
19980
19990
20002
20011
20020
20030
20043
20053
20061
20070
20080
20090
20100
20110
20120
20130
20140
20150
20166
20170
20180
20191
20200
Total229