Frequencies for first 10,000 rows of prescr2 variable in nhamcsed1997 dataset :

prescriptio |
   n status |
   code for |
    drug #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,729       27.29       27.29
          2 |        748        7.48       34.77
          3 |        495        4.95       39.72
          . |      6,028       60.28      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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