Frequencies for first 10,000 rows of dgestat variable in natl1995 dataset :

Gestation - |
  Detail in |
      Weeks |      Freq.     Percent        Cum.
------------+-----------------------------------
         19 |          1        0.01        0.01
         20 |          6        0.06        0.07
         21 |          9        0.09        0.16
         22 |          3        0.03        0.19
         23 |         17        0.17        0.36
         24 |          9        0.09        0.45
         25 |         13        0.13        0.58
         26 |         10        0.10        0.68
         27 |         11        0.11        0.79
         28 |         21        0.21        1.00
         29 |         25        0.25        1.25
         30 |         37        0.37        1.62
         31 |         69        0.69        2.31
         32 |         75        0.75        3.06
         33 |        111        1.11        4.17
         34 |        155        1.55        5.72
         35 |        288        2.88        8.60
         36 |        417        4.17       12.77
         37 |        831        8.31       21.08
         38 |      1,518       15.18       36.26
         39 |      2,238       22.38       58.64
         40 |      2,041       20.41       79.05
         41 |      1,092       10.92       89.97
         42 |        437        4.37       94.34
         43 |        232        2.32       96.66
         44 |        159        1.59       98.25
         45 |         96        0.96       99.21
         46 |         32        0.32       99.53
         47 |         36        0.36       99.89
         99 |         11        0.11      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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