Frequencies for first 10,000 rows of dgestat variable in natlterr2000 dataset :

Gestation - |
  Detail in |
      Weeks |      Freq.     Percent        Cum.
------------+-----------------------------------
         21 |          1        0.01        0.01
         22 |          5        0.05        0.06
         23 |          1        0.01        0.07
         24 |          8        0.08        0.15
         25 |         16        0.16        0.31
         26 |         15        0.15        0.46
         27 |         19        0.19        0.65
         28 |         21        0.21        0.86
         29 |         29        0.29        1.15
         30 |         27        0.27        1.42
         31 |         46        0.46        1.88
         32 |         78        0.78        2.66
         33 |         87        0.87        3.53
         34 |        209        2.09        5.62
         35 |        298        2.98        8.60
         36 |        620        6.20       14.80
         37 |      1,307       13.07       27.87
         38 |      2,146       21.46       49.33
         39 |      2,384       23.84       73.17
         40 |      1,889       18.89       92.06
         41 |        547        5.47       97.53
         42 |        159        1.59       99.12
         43 |         79        0.79       99.91
         44 |          7        0.07       99.98
         99 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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