Frequencies for first 10,000 rows of contsub5 variable in nhamcsed1993 dataset :

 controlled |
  substance |
   code for |
    drug #5 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |          7        0.07        0.07
          3 |          5        0.05        0.12
          4 |         17        0.17        0.29
          5 |          2        0.02        0.31
          6 |        327        3.27        3.58
          7 |         21        0.21        3.79
          . |      9,621       96.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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