Frequencies for first 10,000 rows of blodpres variable in nhamcsopd2004 dataset :

      blood |
   pressure |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      4,038       40.38       40.38
        yes |      5,962       59.62      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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