Frequencies for first 10,000 rows of contsub3 variable in nhamcsed1994 dataset :

 controlled |
  substance |
   code for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |         31        0.31        0.31
          3 |         57        0.57        0.88
          4 |         59        0.59        1.47
          5 |          8        0.08        1.55
          6 |      1,431       14.31       15.86
          7 |        120        1.20       17.06
          . |      8,294       82.94      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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