Frequencies for first 10,000 rows of prescr1 variable in nhamcsed2001 dataset :

prescriptio |
   n status |
   code for |
    drug #1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,777       47.77       47.77
          2 |      1,429       14.29       62.06
          3 |      1,234       12.34       74.40
          . |      2,560       25.60      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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