*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19732
19740
19750
19760
19770
19781
19790
19800
19810
19820
19832
19840
19850
19861
19872
19882
19892
19902
19911
19921
19936
19944
199513
19962
19979
19989
19994
200010
20012
20021
20031
20040
20050
20061
20078
20085
20093
20100
20110
20120
20131
20140
20150
20162
20170
20180
Total97