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

Gestation - |
  Detail in |
  Weeks U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
         18 |          2        0.02        0.02
         20 |          4        0.04        0.06
         21 |          3        0.03        0.09
         22 |          8        0.08        0.17
         23 |          5        0.05        0.22
         24 |         11        0.11        0.33
         25 |         15        0.15        0.48
         26 |         13        0.13        0.61
         27 |         20        0.20        0.81
         28 |         15        0.15        0.96
         29 |         36        0.36        1.32
         30 |         44        0.44        1.76
         31 |         74        0.74        2.50
         32 |         89        0.89        3.39
         33 |        120        1.20        4.59
         34 |        215        2.15        6.74
         35 |        309        3.09        9.83
         36 |        657        6.57       16.40
         37 |      1,460       14.60       31.00
         38 |      2,362       23.62       54.62
         39 |      2,139       21.39       76.01
         40 |      1,353       13.53       89.54
         41 |        538        5.38       94.92
         42 |        225        2.25       97.17
         43 |        133        1.33       98.50
         44 |         74        0.74       99.24
         45 |         36        0.36       99.60
         46 |         13        0.13       99.73
         47 |         20        0.20       99.93
         99 |          7        0.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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