Frequencies for first 10,000 rows of rf_ppoutc variable in natlterr2009 dataset :

       Poor |
  Pregnancy |
Outcome RFP |
588=f_rf_pp |
        o R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      2,449       24.49       24.49
          N |      7,515       75.15       99.64
          U |          2        0.02       99.66
          Y |         34        0.34      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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