Frequencies for first 10,000 rows of oegest_r3 variable in natl2014 dataset :

  Obstetric |
   Estimate |
 Recode 3 1 |
   Under 37 |
      weeks |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        831        8.31        8.31
          2 |      9,148       91.48       99.79
          3 |         21        0.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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