Frequencies for first 10,000 rows of contsub4 variable in namcs1995 dataset :

 controlled |
  substance |
   code for |
 medication |
         #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |          4        0.04        0.04
          3 |         20        0.20        0.24
          4 |         67        0.67        0.91
          5 |          1        0.01        0.92
          6 |      1,105       11.05       11.97
          7 |         40        0.40       12.37
          . |      8,763       87.63      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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