Frequencies for first 10,000 rows of prescr1 variable in nhamcsed1996 dataset :

prescriptio |
   n status |
   code for |
    drug #1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,683       46.83       46.83
          2 |      1,322       13.22       60.05
          3 |        992        9.92       69.97
          . |      3,003       30.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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