Frequencies for first 10,000 rows of otherbld variable in nhamcsed2007 dataset :

other blood |
       test |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      8,006       80.06       80.06
        yes |      1,994       19.94      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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