Frequencies for first 10,000 rows of buncreat variable in nhamcsed2008 dataset :

 bun (blood |
       urea |
nitrogen)/c |
  reatinine |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      7,256       72.56       72.56
        yes |      2,744       27.44      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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