Frequencies for first 10,000 rows of contsub3 variable in nhamcsed1993 dataset :

 controlled |
  substance |
   code for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         45        0.45        0.45
          3 |         63        0.63        1.08
          4 |         37        0.37        1.45
          5 |         11        0.11        1.56
          6 |      1,426       14.26       15.82
          7 |        104        1.04       16.86
          . |      8,314       83.14      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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