Frequencies for first 10,000 rows of monitor variable in natl1994 dataset :

 Electronic |
      fetal |
 monitoring |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      9,137       91.37       91.37
          2 |        846        8.46       99.83
          9 |         17        0.17      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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