Frequencies for first 10,000 rows of prescr2 variable in nhamcsed2001 dataset :

prescriptio |
   n status |
   code for |
    drug #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,987       29.87       29.87
          2 |        800        8.00       37.87
          3 |        608        6.08       43.95
          . |      5,605       56.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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