Frequencies for first 10,000 rows of role_cod variable in drug2009q1 dataset :

   Code for |
     drug's |
   reported |
    role in |
      event |      Freq.     Percent        Cum.
------------+-----------------------------------
          C |      5,217       52.17       52.17
          I |         32        0.32       52.49
         PS |      2,680       26.80       79.29
         SS |      2,071       20.71      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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