Frequencies for first 10,000 rows of prescr3 variable in nhamcsed1994 dataset :

prescriptio |
   n status |
   code for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,213       12.13       12.13
          2 |        277        2.77       14.90
          3 |        216        2.16       17.06
          . |      8,294       82.94      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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