Frequencies for first 10,000 rows of ld_chor variable in natlterr2008 dataset :

Chorioamnio |
  nitis RFP |
613=f_ld_ch |
     orio R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,061       60.61       60.61
          N |      3,928       39.28       99.89
          Y |         11        0.11      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 May 2016