Frequencies for first 10,000 rows of pt variable in nhamcsopd2011 dataset :

   Physical |
    therapy |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,754       97.54       97.54
        Yes |        246        2.46      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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