Frequencies for first 10,000 rows of prescr2 variable in namcs2000 dataset :

prescriptio |
   n status |
   code for |
 medication |
         #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      3,114       31.14       31.14
          2 |        381        3.81       34.95
          3 |        312        3.12       38.07
          . |      6,193       61.93      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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