Frequencies for first 10,000 rows of monitor variable in natlterr1996 dataset :

 Electronic |
      fetal |
 monitoring |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      7,212       72.12       72.12
          2 |      2,783       27.83       99.95
          9 |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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