Frequencies for first 10,000 rows of prescr4 variable in nhamcsed1999 dataset :

prescriptio |
   n status |
   code for |
    drug #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        726        7.26        7.26
          2 |        137        1.37        8.63
          3 |        114        1.14        9.77
          . |      9,023       90.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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