Frequencies for first 10,000 rows of contsub1 variable in namcs1996 dataset :

 controlled |
  substance |
   code for |
 medication |
         #1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        100        1.00        1.00
          3 |        147        1.47        2.47
          4 |        329        3.29        5.76
          5 |         25        0.25        6.01
          6 |      8,978       89.78       95.79
          7 |        401        4.01       99.80
          . |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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