*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
1972139
197367
19740
19751
19760
19770
19781
19790
19800
19811
19820
19831
198485
198553
198690
1987147
1988200
1989132
1990112
1991131
199273
199334
19945
19956
19960
19978
19982
199979
2000147
200157
200236
200320
200425
200515
200621
200712
200816
20097
201019
201126
201214
201324
201415
201523
201634
201724
20181
20190
Total1903