*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19847
19850
19868
198712
198818
198916
199020
199118
199214
199314
199417
199516
199617
199712
199811
199910
20009
200113
20025
20037
20046
20053
20063
20072
20083
20091
20108
20116
20126
20133
20143
20152
20160
20170
20180
20190
20200
Total290