Frequencies for first 10,000 rows of contsub3 variable in nhamcsed1995 dataset :

 controlled |
  substance |
   code for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         69        0.69        0.69
          3 |         69        0.69        1.38
          4 |         60        0.60        1.98
          5 |          5        0.05        2.03
          6 |      1,435       14.35       16.38
          7 |         71        0.71       17.09
          . |      8,291       82.91      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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