Frequencies for first 10,000 rows of prescr2 variable in nhamcsopd1999 dataset :

prescriptio |
   n status |
   code for |
 medication |
         #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,855       28.55       28.55
          2 |        454        4.54       33.09
          3 |        398        3.98       37.07
          . |      6,293       62.93      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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