Frequencies for first 10,000 rows of geste variable in natl1999 dataset :

   Clinical |
estimate of |
  gestation |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |     10,000      100.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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