Frequencies for first 10,000 rows of clingest variable in natl1993 dataset :

   Clinical |
Estimate of |
  Gestation |      Freq.     Percent        Cum.
------------+-----------------------------------
         17 |          1        0.01        0.01
         18 |          3        0.03        0.04
         19 |          2        0.02        0.06
         20 |          4        0.04        0.10
         21 |          2        0.02        0.12
         22 |          5        0.05        0.17
         23 |          4        0.04        0.21
         24 |          9        0.09        0.30
         25 |         19        0.19        0.49
         26 |         18        0.18        0.67
         27 |         21        0.21        0.88
         28 |         22        0.22        1.10
         29 |         12        0.12        1.22
         30 |         21        0.21        1.43
         31 |         31        0.31        1.74
         32 |         61        0.61        2.35
         33 |         60        0.60        2.95
         34 |        104        1.04        3.99
         35 |        208        2.08        6.07
         36 |        337        3.37        9.44
         37 |        640        6.40       15.84
         38 |      1,329       13.29       29.13
         39 |      2,133       21.33       50.46
         40 |      3,679       36.79       87.25
         41 |      1,006       10.06       97.31
         42 |        237        2.37       99.68
         43 |         10        0.10       99.78
         44 |          2        0.02       99.80
         45 |          1        0.01       99.81
         99 |         19        0.19      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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