Frequencies for first 10,000 rows of contsub4 variable in namcs1994 dataset :

 controlled |
  substance |
   code for |
 medication |
         #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |          2        0.02        0.02
          3 |         15        0.15        0.17
          4 |         51        0.51        0.68
          5 |          7        0.07        0.75
          6 |      1,044       10.44       11.19
          7 |         41        0.41       11.60
          . |      8,840       88.40      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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