Frequencies for first 10,000 rows of drg4ing5 variable in nhamcsopd1999 dataset :

 ingredient |
code #5 for |
 medication |
         #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,997       99.97       99.97
      54895 |          1        0.01       99.98
      56185 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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