Frequencies for first 10,000 rows of chow_prior_dt variable in pos1994 dataset :

      prior |
  admission |
 suspension |
       date |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,996       99.96       99.96
     850531 |          1        0.01       99.97
     860430 |          1        0.01       99.98
     860530 |          1        0.01       99.99
     921201 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017