Frequencies for first 10,000 rows of drg3ing4 variable in nhamcsed2001 dataset :

 ingredient |
code #4 for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,986       99.86       99.86
      53175 |          1        0.01       99.87
      54713 |          4        0.04       99.91
      55440 |          1        0.01       99.92
      55755 |          1        0.01       99.93
      56185 |          1        0.01       99.94
      70120 |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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