Frequencies for first 10,000 rows of role_cod variable in drug2009q2 dataset :

   Code for |
     drug's |
   reported |
    role in |
      event |      Freq.     Percent        Cum.
------------+-----------------------------------
            |          1        0.01        0.01
          C |      5,345       53.45       53.46
          D |          5        0.05       53.51
          I |         76        0.76       54.27
         PS |      2,465       24.65       78.92
         SS |      2,108       21.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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