Frequencies for first 10,000 rows of otherbld variable in nhamcsed1997 dataset :

other blood |
       test |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      7,616       76.16       76.16
          1 |      2,384       23.84      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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