Frequencies for first 10,000 rows of contsub6 variable in namcs1995 dataset :

 controlled |
  substance |
   code for |
 medication |
         #6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |          1        0.01        0.01
          3 |          2        0.02        0.03
          4 |         29        0.29        0.32
          5 |          4        0.04        0.36
          6 |        388        3.88        4.24
          7 |          4        0.04        4.28
          . |      9,572       95.72      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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