*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19721
19730
19740
19750
19761
19770
19781
19790
19800
19810
19821
19830
19840
19850
19860
19874
19882
19892
19908
199110
19926
199319
19945
19958
19963
19977
199814
19994
20002
20011
20021
20032
20044
20051
20061
20070
20080
20093
20100
20113
20120
20130
20140
20150
20160
20170
Total114