Frequencies for first 10,000 rows of contsub4 variable in nhamcsed1997 dataset :

 controlled |
  substance |
   code for |
    drug #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         24        0.24        0.24
          3 |         45        0.45        0.69
          4 |         39        0.39        1.08
          5 |          1        0.01        1.09
          6 |        747        7.47        8.56
          7 |         30        0.30        8.86
          . |      9,114       91.14      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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