Frequencies for first 10,000 rows of contsub5 variable in nhamcsed2000 dataset :

 controlled |
  substance |
   code for |
    drug #5 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         21        0.21        0.21
          3 |         14        0.14        0.35
          4 |         20        0.20        0.55
          6 |        416        4.16        4.71
          7 |         22        0.22        4.93
          . |      9,507       95.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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