*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19841
19853
19863
198745
198812
198913
199010
19915
19923
19932
19944
199543
19960
199717
19987
19992
200017
20014
20020
20035
20040
20054
20061
200740
200818
200914
20107
20115
20121
20130
20140
20152
20161
20170
20180
Total289