Frequencies for first 10,000 rows of contsub6 variable in nhamcsed2002 dataset :

 controlled |
  substance |
   code for |
    drug #6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         12        0.12        0.12
          3 |         11        0.11        0.23
          4 |         23        0.23        0.46
          5 |          1        0.01        0.47
          6 |        307        3.07        3.54
          7 |         22        0.22        3.76
          . |      9,624       96.24      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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