*Excludes Observations that spanned multiple years

Pre 19701
19700
19713
197222
197320
19740
19750
19760
19770
19780
19791
19800
19810
19820
19831
19840
19850
198610
198720
198862
198921
199018
199137
199243
199336
199411
199518
19969
199711
19985
199939
200036
200124
200211
20031
20043
20050
20063
20074
20086
200916
20102
20114
20121
20130
20140
20150
20167
20176
20183
20191
20200
Total516