Frequencies for first 10,000 rows of rechal variable in drug2014q1 dataset :

Rechallenge |
      code, |
 indicating |
if reaction |
   recurred |
  when drug |
    therapy |
  restarted |      Freq.     Percent        Cum.
------------+-----------------------------------
            |        755        7.55        7.55
          D |      7,785       77.85       85.40
          N |        481        4.81       90.21
          U |        948        9.48       99.69
          Y |         31        0.31      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 19 Apr 2017