Frequencies for first 10,000 rows of contsub2 variable in nhamcsed2000 dataset :

 controlled |
  substance |
   code for |
    drug #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        206        2.06        2.06
          3 |        207        2.07        4.13
          4 |        121        1.21        5.34
          5 |         10        0.10        5.44
          6 |      3,304       33.04       38.48
          7 |        174        1.74       40.22
          . |      5,978       59.78      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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