Frequencies for first 10,000 rows of contsub3 variable in namcs1999 dataset :

 controlled |
  substance |
   code for |
 medication |
         #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         26        0.26        0.26
          3 |         34        0.34        0.60
          4 |        121        1.21        1.81
          5 |          6        0.06        1.87
          6 |      1,731       17.31       19.18
          7 |         59        0.59       19.77
          . |      8,023       80.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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