Frequencies for first 10,000 rows of contsub3 variable in nhamcsed1992 dataset :

 Controlled |
  substance |
   code for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         31        0.31        0.31
          3 |         37        0.37        0.68
          4 |         27        0.27        0.95
          5 |          4        0.04        0.99
          6 |      1,029       10.29       11.28
          7 |         72        0.72       12.00
          . |      8,800       88.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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