Frequencies for first 10,000 rows of cord variable in natlterr1999 dataset :

       Cord |
   prolapse |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         43        0.43        0.43
          2 |      9,951       99.51       99.94
          9 |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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