Frequencies for first 10,000 rows of contsub3 variable in nhamcsed2001 dataset :

 controlled |
  substance |
   code for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        114        1.14        1.14
          3 |         83        0.83        1.97
          4 |         81        0.81        2.78
          5 |          4        0.04        2.82
          6 |      1,875       18.75       21.57
          7 |         82        0.82       22.39
          . |      7,761       77.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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