Frequencies for first 10,000 rows of blodpres variable in nhamcsopd2001 dataset :

      blood |
   pressure |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      5,264       52.64       52.64
          1 |      4,736       47.36      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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