Frequencies for first 10,000 rows of role_cod variable in drug2004q1 dataset :

   Code for |
     drug's |
   reported |
    role in |
      event |      Freq.     Percent        Cum.
------------+-----------------------------------
          C |      5,906       59.06       59.06
          I |          3        0.03       59.09
         PS |      2,521       25.21       84.30
         SS |      1,570       15.70      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Dec 2015