Frequencies for first 10,000 rows of rechal variable in drug2018q1 dataset :

Rechallenge |
      code, |
 indicating |
if reaction |
   recurred |
  when drug |
    therapy |
  restarted |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,225       82.25       82.25
          N |        224        2.24       84.49
          U |      1,521       15.21       99.70
          Y |         30        0.30      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 19 Jun 2018