Frequencies for first 10,000 rows of otherbld variable in nhamcsed2010 dataset :

Other blood |
       test |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      7,916       79.16       79.16
        yes |      2,084       20.84      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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