Frequencies for first 10,000 rows of gestat3 variable in natl1977 dataset :

  Gestation |
   Recode 3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        867        8.67        8.67
          2 |      7,306       73.06       81.73
          3 |      1,827       18.27      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016