Frequencies for first 10,000 rows of prescr4 variable in nhamcsed1993 dataset :

prescriptio |
   n status |
   code for |
    drug #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        579        5.79        5.79
          2 |        105        1.05        6.84
          3 |         78        0.78        7.62
          . |      9,238       92.38      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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