Frequencies for first 10,000 rows of contsub3 variable in namcs1993 dataset :

 controlled |
  substance |
   code for |
 medication |
         #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         12        0.12        0.12
          3 |         34        0.34        0.46
          4 |         81        0.81        1.27
          5 |         11        0.11        1.38
          6 |      1,611       16.11       17.49
          7 |         71        0.71       18.20
          . |      8,180       81.80      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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