Frequencies for first 10,000 rows of contsub5 variable in nhamcsed1999 dataset :

 controlled |
  substance |
   code for |
    drug #5 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         13        0.13        0.13
          3 |         16        0.16        0.29
          4 |         26        0.26        0.55
          5 |          2        0.02        0.57
          6 |        401        4.01        4.58
          7 |         22        0.22        4.80
          . |      9,520       95.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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