Frequencies for first 10,000 rows of prescr2 variable in nhamcsopd1993 dataset :

prescriptio |
   n status |
   code for |
 medication |
         #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,293       22.93       22.93
          2 |        452        4.52       27.45
          3 |        453        4.53       31.98
          . |      6,802       68.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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