Frequencies for first 10,000 rows of prescr1 variable in nhamcsed1993 dataset :

prescriptio |
   n status |
   code for |
    drug #1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,603       46.03       46.03
          2 |      1,419       14.19       60.22
          3 |      1,066       10.66       70.88
          . |      2,912       29.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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