Frequencies for first 10,000 rows of contsub1 variable in namcs1997 dataset :

 controlled |
  substance |
   code for |
 medication |
         #1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        130        1.30        1.30
          3 |        186        1.86        3.16
          4 |        360        3.60        6.76
          5 |         25        0.25        7.01
          6 |      9,003       90.03       97.04
          7 |        294        2.94       99.98
          . |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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