Frequencies for first 10,000 rows of estgest variable in natlterr2013 dataset :

Obstetric/C |
    linical |
  Gestation |
   Est. RFP |
573=f_cline |
     st U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
         17 |          1        0.01        0.01
         18 |          2        0.02        0.03
         19 |          3        0.03        0.06
         20 |          7        0.07        0.13
         22 |          2        0.02        0.15
         23 |          2        0.02        0.17
         24 |          3        0.03        0.20
         25 |          8        0.08        0.28
         26 |          7        0.07        0.35
         27 |         11        0.11        0.46
         28 |         15        0.15        0.61
         29 |         16        0.16        0.77
         30 |         29        0.29        1.06
         31 |         33        0.33        1.39
         32 |         43        0.43        1.82
         33 |         56        0.56        2.38
         34 |        117        1.17        3.55
         35 |        179        1.79        5.34
         36 |        401        4.01        9.35
         37 |        991        9.91       19.26
         38 |      2,272       22.72       41.98
         39 |      2,656       26.56       68.54
         40 |      1,549       15.49       84.03
         41 |        341        3.41       87.44
         42 |         41        0.41       87.85
         43 |          3        0.03       87.88
         44 |          1        0.01       87.89
         45 |          2        0.02       87.91
         99 |      1,209       12.09      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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