Frequencies for first 10,000 rows of role_cod variable in drug2011q1 dataset :

   Code for |
     drug's |
   reported |
    role in |
      event |      Freq.     Percent        Cum.
------------+-----------------------------------
            |          1        0.01        0.01
          C |      4,946       49.46       49.47
          D |          4        0.04       49.51
          I |         80        0.80       50.31
         PS |      2,598       25.98       76.29
         SS |      2,371       23.71      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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