Frequencies for first 10,000 rows of ab_aven6 variable in natlterr2013 dataset :

   Assisted |
Ventilation |
 >6 hrs RFP |
629=f_ab_ve |
      nt6 R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      1,077       10.77       10.77
          N |      8,499       84.99       95.76
          U |        333        3.33       99.09
          Y |         91        0.91      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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