*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19832
19840
19850
19861
19872
19882
19892
19901
19911
19921
19936
19944
199512
19962
19979
19989
19994
20009
20012
20021
20031
20040
20050
20061
20078
20085
20093
20100
20110
20120
20130
20140
20150
20160
20170
Total88