Frequencies for first 10,000 rows of prescr2 variable in nhamcsed1998 dataset :

prescriptio |
   n status |
   code for |
    drug #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,653       26.53       26.53
          2 |        721        7.21       33.74
          3 |        396        3.96       37.70
          . |      6,230       62.30      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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