Frequencies for first 10,000 rows of contsub5 variable in nhamcsed1994 dataset :

 controlled |
  substance |
   code for |
    drug #5 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |          6        0.06        0.06
          3 |          8        0.08        0.14
          4 |         16        0.16        0.30
          6 |        336        3.36        3.66
          7 |         38        0.38        4.04
          . |      9,596       95.96      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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