Frequencies for first 10,000 rows of gestrec3 variable in natl2014 dataset :

   Combined |
  Gestation |
 Recode 3 1 |
   Under 37 |
      weeks |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        987        9.87        9.87
          2 |      8,992       89.92       99.79
          3 |         21        0.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 15 Jun 2016