*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19721
19730
19740
19750
19761
19770
19780
19790
19801
19810
19820
19831
19840
19851
19864
198710
19884
19893
199010
19915
199212
199318
199425
199514
19960
19973
19982
19990
20000
20014
20026
20034
20040
200515
20063
20070
200820
20091
20103
20110
20120
20130
20140
20152
20164
20171
20180
Total179