Frequencies for first 10,000 rows of dgestat variable in natl1992 dataset :

Gestation - |
  Detail in |
      Weeks |      Freq.     Percent        Cum.
------------+-----------------------------------
         18 |          1        0.01        0.01
         19 |          2        0.02        0.03
         20 |          9        0.09        0.12
         21 |          5        0.05        0.17
         22 |          3        0.03        0.20
         23 |          6        0.06        0.26
         24 |         12        0.12        0.38
         25 |         20        0.20        0.58
         26 |         12        0.12        0.70
         27 |         18        0.18        0.88
         28 |         36        0.36        1.24
         29 |         25        0.25        1.49
         30 |         39        0.39        1.88
         31 |         47        0.47        2.35
         32 |         86        0.86        3.21
         33 |        103        1.03        4.24
         34 |        192        1.92        6.16
         35 |        295        2.95        9.11
         36 |        443        4.43       13.54
         37 |        659        6.59       20.13
         38 |      1,296       12.96       33.09
         39 |      2,143       21.43       54.52
         40 |      2,144       21.44       75.96
         41 |      1,272       12.72       88.68
         42 |        553        5.53       94.21
         43 |        245        2.45       96.66
         44 |        170        1.70       98.36
         45 |         89        0.89       99.25
         46 |         43        0.43       99.68
         47 |         25        0.25       99.93
         99 |          7        0.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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