Frequencies for first 10,000 rows of contsub6 variable in namcs1997 dataset :

 controlled |
  substance |
   code for |
 medication |
         #6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |          4        0.04        0.04
          3 |          9        0.09        0.13
          4 |         30        0.30        0.43
          5 |          1        0.01        0.44
          6 |        521        5.21        5.65
          7 |          4        0.04        5.69
          . |      9,431       94.31      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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