Frequencies for first 10,000 rows of rechal variable in drug2014q2 dataset :

Rechallenge |
      code, |
 indicating |
if reaction |
   recurred |
  when drug |
    therapy |
  restarted |      Freq.     Percent        Cum.
------------+-----------------------------------
            |        655        6.55        6.55
          D |      8,131       81.31       87.86
          N |        203        2.03       89.89
          U |        985        9.85       99.74
          Y |         26        0.26      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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