Frequencies for first 10,000 rows of prescr4 variable in nhamcsopd1999 dataset :

prescriptio |
   n status |
   code for |
 medication |
         #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        972        9.72        9.72
          2 |        150        1.50       11.22
          3 |         91        0.91       12.13
          . |      8,787       87.87      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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