*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19830
19840
19850
19860
19871
19885
19893
19900
19911
19921
199310
19942
199525
19960
19972
19980
19993
20001
20011
20023
20032
20040
20051
20062
20070
20082
20093
20104
20116
20127
20130
20141
20153
20162
20177
20181
20190
20201
20214
20226
20239
20243
Total123