Frequencies for first 10,000 rows of contsub5 variable in nhamcsopd1996 dataset :

 controlled |
  substance |
   code for |
 medication |
         #5 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |          5        0.05        0.05
          3 |         11        0.11        0.16
          4 |         32        0.32        0.48
          5 |          2        0.02        0.50
          6 |        691        6.91        7.41
          7 |         34        0.34        7.75
          . |      9,225       92.25      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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