Frequencies for first 10,000 rows of ab_aven1 variable in natl2015 dataset :

   Assisted |
Ventilation |
(immediatel |
   y) Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,185       91.85       91.85
          U |        106        1.06       92.91
          Y |        709        7.09      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Oct 2016