Frequencies for first 10,000 rows of oegest_r3 variable in natl2015 dataset :

  Obstetric |
   Estimate |
 Recode 3 1 |
   Under 37 |
      weeks |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        888        8.88        8.88
          2 |      9,102       91.02       99.90
          3 |         10        0.10      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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