Frequencies for first 10,000 rows of combgest variable in natlterr2005 dataset :

Gestation - |
  Detail in |
  Weeks U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
         17 |          2        0.02        0.02
         19 |          2        0.02        0.04
         20 |          1        0.01        0.05
         21 |          4        0.04        0.09
         22 |          5        0.05        0.14
         23 |         12        0.12        0.26
         24 |          7        0.07        0.33
         25 |          8        0.08        0.41
         26 |         14        0.14        0.55
         27 |         15        0.15        0.70
         28 |         21        0.21        0.91
         29 |         31        0.31        1.22
         30 |         38        0.38        1.60
         31 |         43        0.43        2.03
         32 |         63        0.63        2.66
         33 |        143        1.43        4.09
         34 |        191        1.91        6.00
         35 |        309        3.09        9.09
         36 |        456        4.56       13.65
         37 |        924        9.24       22.89
         38 |      1,752       17.52       40.41
         39 |      1,843       18.43       58.84
         40 |      1,247       12.47       71.31
         41 |        598        5.98       77.29
         42 |        258        2.58       79.87
         43 |        132        1.32       81.19
         44 |         73        0.73       81.92
         45 |         41        0.41       82.33
         46 |         20        0.20       82.53
         47 |         21        0.21       82.74
         99 |      1,726       17.26      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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