Frequencies for first 10,000 rows of abg variable in nhamcsed2005 dataset :

   arteriel |
blood gases |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,664       96.64       96.64
        yes |        336        3.36      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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