*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19726
19735
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19841
198514
19863
198720
198819
19894
199024
199123
199213
199312
19940
19950
19960
19973
19980
199913
20007
20014
20021
20030
200431
20053
20060
20072
20088
20093
20102
20111
20121
20130
20144
20152
20163
20175
20180
Total238