Frequencies for first 10,000 rows of contsub3 variable in nhamcsed2000 dataset :

 controlled |
  substance |
   code for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         95        0.95        0.95
          3 |         99        0.99        1.94
          4 |         68        0.68        2.62
          5 |          6        0.06        2.68
          6 |      1,649       16.49       19.17
          7 |         92        0.92       20.09
          . |      7,991       79.91      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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