Frequencies for first 10,000 rows of contsub1 variable in nhamcsed1999 dataset :

 controlled |
  substance |
   code for |
    drug #1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        337        3.37        3.37
          3 |        349        3.49        6.86
          4 |        203        2.03        8.89
          5 |         15        0.15        9.04
          6 |      5,745       57.45       66.49
          7 |        224        2.24       68.73
          . |      3,127       31.27      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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