Frequencies for first 10,000 rows of prescr3 variable in nhamcsed1999 dataset :

prescriptio |
   n status |
   code for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,469       14.69       14.69
          2 |        303        3.03       17.72
          3 |        265        2.65       20.37
          . |      7,963       79.63      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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