Frequencies for first 10,000 rows of contsub4 variable in nhamcsed2000 dataset :

 controlled |
  substance |
   code for |
    drug #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         41        0.41        0.41
          3 |         39        0.39        0.80
          4 |         28        0.28        1.08
          5 |          2        0.02        1.10
          6 |        808        8.08        9.18
          7 |         42        0.42        9.60
          . |      9,040       90.40      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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