Frequencies for first 10,000 rows of prescr2 variable in nhamcsed1993 dataset :

prescriptio |
   n status |
   code for |
    drug #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,444       24.44       24.44
          2 |        758        7.58       32.02
          3 |        414        4.14       36.16
          . |      6,384       63.84      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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