Frequencies for first 10,000 rows of blodpres variable in namcs2003 dataset :

      blood |
   pressure |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      5,834       58.34       58.34
          1 |      4,166       41.66      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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