Frequencies for first 10,000 rows of contsub4 variable in nhamcsed1999 dataset :

 controlled |
  substance |
   code for |
    drug #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         34        0.34        0.34
          3 |         37        0.37        0.71
          4 |         40        0.40        1.11
          5 |          2        0.02        1.13
          6 |        808        8.08        9.21
          7 |         56        0.56        9.77
          . |      9,023       90.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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