Frequencies for first 10,000 rows of contsub1 variable in nhamcsed2002 dataset :

 controlled |
  substance |
   code for |
    drug #1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        409        4.09        4.09
          3 |        283        2.83        6.92
          4 |        201        2.01        8.93
          5 |          8        0.08        9.01
          6 |      6,217       62.17       71.18
          7 |        181        1.81       72.99
          . |      2,701       27.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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