Frequencies for first 10,000 rows of contsub23 variable in namcs2015 dataset :

 Controlled |
  substance |
   code for |
 medication |
        #23 |      Freq.     Percent        Cum.
------------+-----------------------------------
          3 |          1        0.01        0.01
          6 |         23        0.23        0.24
          7 |          1        0.01        0.25
          . |      9,975       99.75      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 25 Oct 2017