Frequencies for first 10,000 rows of abg variable in nhamcsed2011 dataset :

   Arterial |
blood gases |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,469       94.69       94.69
        Yes |        531        5.31      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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