Frequencies for first 10,000 rows of contsub2 variable in namcs1994 dataset :

 controlled |
  substance |
   code for |
 medication |
         #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         11        0.11        0.11
          3 |        115        1.15        1.26
          4 |        160        1.60        2.86
          5 |         43        0.43        3.29
          6 |      3,747       37.47       40.76
          7 |        179        1.79       42.55
          . |      5,745       57.45      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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