Frequencies for first 10,000 rows of contsub5 variable in nhamcsed1998 dataset :

 controlled |
  substance |
   code for |
    drug #5 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         13        0.13        0.13
          3 |          9        0.09        0.22
          4 |         21        0.21        0.43
          5 |          1        0.01        0.44
          6 |        324        3.24        3.68
          7 |          8        0.08        3.76
          . |      9,624       96.24      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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