Frequencies for first 10,000 rows of oegest_r10 variable in natlterr2015 dataset :

  Obstetric |
   Estimate |
Recode10 01 |
   Under 20 |
      weeks |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          1        0.01        0.01
          2 |         48        0.48        0.49
          3 |         87        0.87        1.36
          4 |         99        0.99        2.35
          5 |        648        6.48        8.83
          6 |      3,005       30.05       38.88
          7 |      2,814       28.14       67.02
          8 |      1,708       17.08       84.10
          9 |        432        4.32       88.42
         10 |      1,126       11.26       99.68
         99 |         32        0.32      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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