Frequencies for first 10,000 rows of prescr2 variable in namcs1999 dataset :

prescriptio |
   n status |
   code for |
 medication |
         #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      3,063       30.63       30.63
          2 |        322        3.22       33.85
          3 |        237        2.37       36.22
          . |      6,378       63.78      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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