Frequencies for first 10,000 rows of estgest variable in natlterr2007 dataset :

Obstetric/C |
    linical |
  Gestation |
   Est. RFP |
573=f_cline |
     st U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
         18 |          2        0.02        0.02
         19 |          1        0.01        0.03
         20 |          1        0.01        0.04
         21 |          1        0.01        0.05
         22 |          7        0.07        0.12
         23 |          7        0.07        0.19
         24 |          7        0.07        0.26
         25 |          6        0.06        0.32
         26 |         10        0.10        0.42
         27 |         13        0.13        0.55
         28 |         12        0.12        0.67
         29 |         17        0.17        0.84
         30 |         22        0.22        1.06
         31 |         37        0.37        1.43
         32 |         61        0.61        2.04
         33 |         79        0.79        2.83
         34 |        161        1.61        4.44
         35 |        248        2.48        6.92
         36 |        511        5.11       12.03
         37 |      1,171       11.71       23.74
         38 |      2,188       21.88       45.62
         39 |      2,078       20.78       66.40
         40 |      1,421       14.21       80.61
         41 |        441        4.41       85.02
         42 |        101        1.01       86.03
         43 |         27        0.27       86.30
         44 |         17        0.17       86.47
         45 |          2        0.02       86.49
         47 |          1        0.01       86.50
         99 |      1,350       13.50      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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