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

  Premature |
 Rupture of |
   Membrane |
        RFP |
605=f_on_ru |
    pture R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,275       62.75       62.75
          N |      3,676       36.76       99.51
          Y |         49        0.49      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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