Frequencies for first 10,000 rows of contsub6 variable in nhamcsed2001 dataset :

 controlled |
  substance |
   code for |
    drug #6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |          8        0.08        0.08
          3 |          6        0.06        0.14
          4 |         18        0.18        0.32
          5 |          1        0.01        0.33
          6 |        286        2.86        3.19
          7 |         22        0.22        3.41
          . |      9,659       96.59      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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