*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
197210
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19830
19840
198512
198613
198725
198841
19899
199064
1991102
199278
19938
19946
199517
19962
19973
19980
199910
200017
200112
20024
20030
200431
20055
20061
20070
20086
20090
20104
20110
20126
20134
20142
20151
20164
20173
20180
20190
Total501