Frequencies for first 10,000 rows of contsub5 variable in nhamcsopd2001 dataset :

 controlled |
  substance |
   code for |
 medication |
         #5 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         33        0.33        0.33
          3 |          8        0.08        0.41
          4 |         34        0.34        0.75
          5 |          1        0.01        0.76
          6 |        889        8.89        9.65
          7 |         49        0.49       10.14
          . |      8,986       89.86      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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