Frequencies for first 10,000 rows of rf_ppoutc variable in linkpe2009psden dataset :

       Poor |
  Pregnancy |
  Outcome R |
  (f_rf_ppo |
  rep flag) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      3,422       34.22       34.22
          N |      6,542       65.42       99.64
          U |          1        0.01       99.65
          Y |         35        0.35      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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