Frequencies for first 10,000 rows of drg6ing4 variable in nhamcsopd1997 dataset :

 ingredient |
code #4 for |
 medication |
         #6 |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,996       99.96       99.96
      53175 |          1        0.01       99.97
      55755 |          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