Frequencies for first 10,000 rows of monitor variable in natlterr2000 dataset :

 Electronic |
      fetal |
 monitoring |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      8,184       81.84       81.84
          2 |      1,810       18.10       99.94
          9 |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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