Frequencies for first 10,000 rows of prescra2 variable in nhamcsed2001 dataset :

prescriptio |
   n status |
   code for |
    adverse |
    drug #2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         34        0.34        0.34
          2 |          3        0.03        0.37
          3 |          8        0.08        0.45
          4 |         16        0.16        0.61
          . |      9,939       99.39      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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