Frequencies for first 10,000 rows of clingest variable in natl1995 dataset :

   Clinical |
Estimate of |
  Gestation |      Freq.     Percent        Cum.
------------+-----------------------------------
         18 |          1        0.01        0.01
         19 |          2        0.02        0.03
         20 |          6        0.06        0.09
         21 |          5        0.05        0.14
         22 |          1        0.01        0.15
         23 |         11        0.11        0.26
         24 |         13        0.13        0.39
         25 |         15        0.15        0.54
         26 |          7        0.07        0.61
         27 |         21        0.21        0.82
         28 |         17        0.17        0.99
         29 |         13        0.13        1.12
         30 |         26        0.26        1.38
         31 |         41        0.41        1.79
         32 |         57        0.57        2.36
         33 |         64        0.64        3.00
         34 |        115        1.15        4.15
         35 |        200        2.00        6.15
         36 |        380        3.80        9.95
         37 |        683        6.83       16.78
         38 |      1,399       13.99       30.77
         39 |      2,293       22.93       53.70
         40 |      3,387       33.87       87.57
         41 |        990        9.90       97.47
         42 |        215        2.15       99.62
         43 |         17        0.17       99.79
         44 |          2        0.02       99.81
         99 |         19        0.19      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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