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

   Combined |
Gestation - |
  Detail in |
Weeks 17-47 |
       17th |
    through |
  47th week |
         of |      Freq.     Percent        Cum.
------------+-----------------------------------
         21 |          4        0.04        0.04
         22 |          4        0.04        0.08
         23 |          6        0.06        0.14
         24 |          6        0.06        0.20
         25 |         13        0.13        0.33
         26 |          7        0.07        0.40
         27 |          6        0.06        0.46
         28 |         10        0.10        0.56
         29 |         15        0.15        0.71
         30 |         25        0.25        0.96
         31 |         32        0.32        1.28
         32 |         40        0.40        1.68
         33 |         79        0.79        2.47
         34 |        140        1.40        3.87
         35 |        208        2.08        5.95
         36 |        392        3.92        9.87
         37 |        928        9.28       19.15
         38 |      1,533       15.33       34.48
         39 |      2,536       25.36       59.84
         40 |      2,138       21.38       81.22
         41 |      1,194       11.94       93.16
         42 |        333        3.33       96.49
         43 |        152        1.52       98.01
         44 |         89        0.89       98.90
         45 |         47        0.47       99.37
         46 |         24        0.24       99.61
         47 |         18        0.18       99.79
         99 |         21        0.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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