Frequencies for first 10,000 rows of prescr2 variable in nhamcsed1992 dataset :

Prescriptio |
   n status |
   code for |
    drug #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,937       19.37       19.37
          2 |        681        6.81       26.18
          3 |        416        4.16       30.34
          . |      6,966       69.66      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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