Frequencies for first 10,000 rows of pttinr variable in nhamcsed2015 dataset :

Prothrombin |
   time/INR |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,102       91.02       91.02
        Yes |        898        8.98      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Nov 2017