Frequencies for first 10,000 rows of contsub2 variable in namcs1998 dataset :

 controlled |
  substance |
   code for |
 medication |
         #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         30        0.30        0.30
          3 |         67        0.67        0.97
          4 |        103        1.03        2.00
          5 |         59        0.59        2.59
          6 |      3,182       31.82       34.41
          7 |         94        0.94       35.35
          . |      6,465       64.65      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016