Frequencies for first 10,000 rows of contsub1 variable in namcs2000 dataset :

 controlled |
  substance |
   code for |
 medication |
         #1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         86        0.86        0.86
          3 |        102        1.02        1.88
          4 |        136        1.36        3.24
          5 |         22        0.22        3.46
          6 |      6,073       60.73       64.19
          7 |        263        2.63       66.82
          . |      3,318       33.18      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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