Frequencies for first 10,000 rows of dgestat variable in natl1994 dataset :

Gestation - |
  Detail in |
      Weeks |      Freq.     Percent        Cum.
------------+-----------------------------------
         19 |          4        0.04        0.04
         20 |          4        0.04        0.08
         21 |          5        0.05        0.13
         22 |          7        0.07        0.20
         23 |          9        0.09        0.29
         24 |         11        0.11        0.40
         25 |         16        0.16        0.56
         26 |         10        0.10        0.66
         27 |         17        0.17        0.83
         28 |         28        0.28        1.11
         29 |         33        0.33        1.44
         30 |         56        0.56        2.00
         31 |         71        0.71        2.71
         32 |         90        0.90        3.61
         33 |        107        1.07        4.68
         34 |        211        2.11        6.79
         35 |        274        2.74        9.53
         36 |        465        4.65       14.18
         37 |        776        7.76       21.94
         38 |      1,365       13.65       35.59
         39 |      2,191       21.91       57.50
         40 |      2,040       20.40       77.90
         41 |      1,192       11.92       89.82
         42 |        452        4.52       94.34
         43 |        240        2.40       96.74
         44 |        165        1.65       98.39
         45 |         92        0.92       99.31
         46 |         41        0.41       99.72
         47 |         20        0.20       99.92
         99 |          8        0.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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