Frequencies for first 10,000 rows of gestrec3 variable in natl2015 dataset :

   Combined |
  Gestation |
 Recode 3 1 |
   Under 37 |
      weeks |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,022       10.22       10.22
          2 |      8,968       89.68       99.90
          3 |         10        0.10      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Oct 2016