Frequencies for first 10,000 rows of role_cod variable in drug2010q2 dataset :

   Code for |
     drug's |
   reported |
    role in |
      event |      Freq.     Percent        Cum.
------------+-----------------------------------
            |          2        0.02        0.02
          C |      5,048       50.48       50.50
          D |          5        0.05       50.55
          I |         59        0.59       51.14
         PS |      2,513       25.13       76.27
         SS |      2,373       23.73      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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