Frequencies for first 10,000 rows of estgest variable in linkpe2009psden dataset :

Obstetric/C |
    linical |
  Gestation |
   Est. U;R |
 (f_estgest |
  rep flag) |      Freq.     Percent        Cum.
------------+-----------------------------------
         14 |          1        0.01        0.01
         15 |          1        0.01        0.02
         18 |          1        0.01        0.03
         20 |          4        0.04        0.07
         21 |          3        0.03        0.10
         22 |          8        0.08        0.18
         23 |          4        0.04        0.22
         24 |          8        0.08        0.30
         25 |         13        0.13        0.43
         26 |         10        0.10        0.53
         27 |         15        0.15        0.68
         28 |         18        0.18        0.86
         29 |         37        0.37        1.23
         30 |         43        0.43        1.66
         31 |         45        0.45        2.11
         32 |         59        0.59        2.70
         33 |         86        0.86        3.56
         34 |        165        1.65        5.21
         35 |        258        2.58        7.79
         36 |        623        6.23       14.02
         37 |      1,489       14.89       28.91
         38 |      2,591       25.91       54.82
         39 |      2,387       23.87       78.69
         40 |      1,436       14.36       93.05
         41 |        465        4.65       97.70
         42 |        127        1.27       98.97
         43 |         47        0.47       99.44
         44 |         14        0.14       99.58
         45 |          6        0.06       99.64
         47 |          1        0.01       99.65
         99 |         35        0.35      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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