Frequencies for first 10,000 rows of blodpres variable in nhamcsopd1996 dataset :

      blood |
   pressure |
       test |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,467       44.67       44.67
          1 |      5,533       55.33      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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