Frequencies for first 10,000 rows of ab_aven1 variable in natlterr2006 dataset :

   Assisted |
Ventilation |
        RFP |
628=f_ab_ve |
       nt R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,275       62.75       62.75
          N |      3,641       36.41       99.16
          Y |         84        0.84      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015