Frequencies for first 10,000 rows of prescr2 variable in nhamcsed1994 dataset :

prescriptio |
   n status |
   code for |
    drug #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,524       25.24       25.24
          2 |        752        7.52       32.76
          3 |        502        5.02       37.78
          . |      6,222       62.22      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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