Frequencies for first 10,000 rows of pttinr variable in nhamcsed2014 dataset :

Prothrombin |
   time/INR |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,191       91.91       91.91
        Yes |        809        8.09      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 11 Apr 2017