Frequencies for first 10,000 rows of pttinr variable in nhamcsed2011 dataset :

Prothrombin |
   time/INR |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      8,897       88.97       88.97
        Yes |      1,103       11.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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