Frequencies for first 10,000 rows of drg4ing4 variable in nhamcsed2000 dataset :

 ingredient |
code #4 for |
    drug #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,989       99.89       99.89
      54455 |          1        0.01       99.90
      54713 |          2        0.02       99.92
      55180 |          6        0.06       99.98
      56193 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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