Frequencies for first 10,000 rows of prescr4 variable in nhamcsed1998 dataset :

prescriptio |
   n status |
   code for |
    drug #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        588        5.88        5.88
          2 |        116        1.16        7.04
          3 |         76        0.76        7.80
          . |      9,220       92.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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