Frequencies for first 10,000 rows of contsub3 variable in nhamcsed1996 dataset :

 controlled |
  substance |
   code for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         85        0.85        0.85
          3 |         80        0.80        1.65
          4 |         73        0.73        2.38
          5 |          8        0.08        2.46
          6 |      1,608       16.08       18.54
          7 |         81        0.81       19.35
          . |      8,065       80.65      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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