Frequencies for first 10,000 rows of contsub2 variable in nhamcsed2002 dataset :

 controlled |
  substance |
   code for |
    drug #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        231        2.31        2.31
          3 |        165        1.65        3.96
          4 |        137        1.37        5.33
          5 |         14        0.14        5.47
          6 |      3,538       35.38       40.85
          7 |        151        1.51       42.36
          . |      5,764       57.64      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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