Frequencies for first 10,000 rows of drg3ing4 variable in nhamcsed1999 dataset :

 ingredient |
code #4 for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,981       99.81       99.81
      51340 |          2        0.02       99.83
      54595 |          1        0.01       99.84
      54713 |          3        0.03       99.87
      55180 |         10        0.10       99.97
      56193 |          1        0.01       99.98
      56265 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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