Frequencies for first 10,000 rows of abg variable in nhamcsed2015 dataset :

   Arterial |
blood gases |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,760       97.60       97.60
        Yes |        240        2.40      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Nov 2017