Frequencies for first 10,000 rows of prescr1 variable in nhamcsopd1993 dataset :

prescriptio |
   n status |
   code for |
 medication |
         #1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,220       42.20       42.20
          2 |        607        6.07       48.27
          3 |        817        8.17       56.44
          . |      4,356       43.56      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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