*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19830
19840
19859
198613
19873
19880
19890
19900
19910
19926
19931
19946
199517
19962
19973
19980
19993
20007
20014
20024
20030
200431
20055
20061
20070
20086
20090
20103
20110
20126
20133
20142
20151
20164
20172
20180
Total143