Frequencies for first 10,000 rows of drg4ing4 variable in nhamcsed1997 dataset :

 ingredient |
code #4 for |
    drug #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,997       99.97       99.97
      55105 |          1        0.01       99.98
      55180 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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