Frequencies for first 10,000 rows of role_cod variable in drug2008q4 dataset :

   Code for |
     drug's |
   reported |
    role in |
      event |      Freq.     Percent        Cum.
------------+-----------------------------------
            |          1        0.01        0.01
          C |      5,299       52.99       53.00
          D |          3        0.03       53.03
          I |         43        0.43       53.46
         PS |      2,699       26.99       80.45
         SS |      1,955       19.55      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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