Frequencies for first 10,000 rows of contsub1 variable in nhamcsed2001 dataset :

 controlled |
  substance |
   code for |
    drug #1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        406        4.06        4.06
          3 |        315        3.15        7.21
          4 |        209        2.09        9.30
          5 |          6        0.06        9.36
          6 |      6,300       63.00       72.36
          7 |        204        2.04       74.40
          . |      2,560       25.60      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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