Frequencies for first 10,000 rows of contsub5 variable in nhamcsopd2000 dataset :

 controlled |
  substance |
   code for |
 medication |
         #5 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         24        0.24        0.24
          3 |         10        0.10        0.34
          4 |         34        0.34        0.68
          5 |          2        0.02        0.70
          6 |        836        8.36        9.06
          7 |         24        0.24        9.30
          . |      9,070       90.70      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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