Frequencies for first 10,000 rows of dgestat variable in natl1999 dataset :

Gestation - |
  Detail in |
      Weeks |      Freq.     Percent        Cum.
------------+-----------------------------------
         19 |          3        0.03        0.03
         20 |          8        0.08        0.11
         21 |          4        0.04        0.15
         22 |          9        0.09        0.24
         23 |          8        0.08        0.32
         24 |         16        0.16        0.48
         25 |         15        0.15        0.63
         26 |         21        0.21        0.84
         27 |         14        0.14        0.98
         28 |         22        0.22        1.20
         29 |         30        0.30        1.50
         30 |         55        0.55        2.05
         31 |         75        0.75        2.80
         32 |         78        0.78        3.58
         33 |        104        1.04        4.62
         34 |        190        1.90        6.52
         35 |        286        2.86        9.38
         36 |        483        4.83       14.21
         37 |        818        8.18       22.39
         38 |      1,762       17.62       40.01
         39 |      2,315       23.15       63.16
         40 |      1,885       18.85       82.01
         41 |        962        9.62       91.63
         42 |        368        3.68       95.31
         43 |        198        1.98       97.29
         44 |        127        1.27       98.56
         45 |         80        0.80       99.36
         46 |         33        0.33       99.69
         47 |         21        0.21       99.90
         99 |         10        0.10      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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