Frequencies for first 10,000 rows of contsub4 variable in namcs2015 dataset :

 Controlled |
  substance |
   code for |
 medication |
         #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         27        0.27        0.27
          3 |         29        0.29        0.56
          4 |         79        0.79        1.35
          5 |          8        0.08        1.43
          6 |      2,982       29.82       31.25
          7 |         65        0.65       31.90
          8 |         10        0.10       32.00
          . |      6,800       68.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 25 Oct 2017