Frequencies for first 10,000 rows of drg3ing4 variable in nhamcsed1996 dataset :

 ingredient |
code #4 for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,977       99.77       99.77
      54713 |          7        0.07       99.84
      55180 |         14        0.14       99.98
      55755 |          1        0.01       99.99
      56265 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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