Frequencies for first 10,000 rows of blodpres variable in nhamcsopd2003 dataset :

      blood |
   pressure |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      4,820       48.20       48.20
        yes |      5,180       51.80      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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