Frequencies for first 10,000 rows of blodpres variable in nhamcsopd1994 dataset :

      blood |
   pressure |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,401       44.01       44.01
          1 |      5,599       55.99      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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