*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19731
19740
19750
19761
19770
19780
19790
19800
19810
19820
19832
19841
19850
19861
19870
19881
19890
19904
19914
19927
19933
19947
199513
19964
19977
19984
19994
20005
20013
20021
20030
20040
20050
20063
20072
20080
20090
20103
20110
20120
20130
20140
20150
20160
20170
Total81