Frequencies for first 10,000 rows of dgestat variable in natl2000 dataset :

Gestation - |
  Detail in |
      Weeks |      Freq.     Percent        Cum.
------------+-----------------------------------
         19 |          2        0.02        0.02
         20 |          1        0.01        0.03
         21 |          9        0.09        0.12
         22 |          4        0.04        0.16
         23 |         10        0.10        0.26
         24 |          9        0.09        0.35
         25 |         15        0.15        0.50
         26 |         23        0.23        0.73
         27 |         27        0.27        1.00
         28 |         14        0.14        1.14
         29 |         27        0.27        1.41
         30 |         51        0.51        1.92
         31 |         60        0.60        2.52
         32 |         66        0.66        3.18
         33 |        118        1.18        4.36
         34 |        214        2.14        6.50
         35 |        296        2.96        9.46
         36 |        542        5.42       14.88
         37 |        944        9.44       24.32
         38 |      1,755       17.55       41.87
         39 |      2,404       24.04       65.91
         40 |      1,799       17.99       83.90
         41 |        848        8.48       92.38
         42 |        290        2.90       95.28
         43 |        204        2.04       97.32
         44 |        120        1.20       98.52
         45 |         75        0.75       99.27
         46 |         40        0.40       99.67
         47 |         23        0.23       99.90
         99 |         10        0.10      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015