Frequencies for first 10,000 rows of prescr1 variable in nhamcsed1994 dataset :

prescriptio |
   n status |
   code for |
    drug #1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,607       46.07       46.07
          2 |      1,454       14.54       60.61
          3 |      1,186       11.86       72.47
          . |      2,753       27.53      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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