Frequencies for first 10,000 rows of contsub3 variable in nhamcsed1997 dataset :

 controlled |
  substance |
   code for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         76        0.76        0.76
          3 |         71        0.71        1.47
          4 |         75        0.75        2.22
          5 |          7        0.07        2.29
          6 |      1,566       15.66       17.95
          7 |         63        0.63       18.58
          . |      8,142       81.42      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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