*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
199115
19924
19931
19948
19954
19963
19973
19989
19993
20002
20018
20020
20031
20042
20050
20062
20071
20080
20091
20100
20111
20120
20130
20140
20150
20169
20171
20180
Total78