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

   Trial of |
      Labor |
  Attempted |
        (if |
cesarean) Y |
        Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      1,376       13.76       13.76
          U |         97        0.97       14.73
          X |      7,639       76.39       91.12
          Y |        888        8.88      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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