*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19721
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19871
19884
19898
199019
199118
19923
199310
199411
19954
199618
19978
19980
19993
20000
20011
20022
20031
20040
20050
20061
20070
20083
20090
20104
20116
20120
20130
20140
20150
20160
20171
Total127