Frequencies for first 10,000 rows of blodpres variable in nhamcsopd2008 dataset :

      blood |
   pressure |
      taken |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      3,628       36.28       36.28
        yes |      6,372       63.72      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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