Frequencies for first 10,000 rows of ab_aven1 variable in natl2014 dataset :

   Assisted |
Ventilation |
(immediatel |
   y) Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,322       93.22       93.22
          U |        269        2.69       95.91
          Y |        409        4.09      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 15 Jun 2016