Frequencies for first 10,000 rows of prescr3 variable in nhamcsed2000 dataset :

prescriptio |
   n status |
   code for |
    drug #3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,422       14.22       14.22
          2 |        324        3.24       17.46
          3 |        263        2.63       20.09
          . |      7,991       79.91      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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