Frequencies for first 10,000 rows of gestrec10 variable in natl2009 dataset :

  Gestation |
  Recode 10 |
        U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          4        0.04        0.04
          2 |         63        0.63        0.67
          3 |        146        1.46        2.13
          4 |        151        1.51        3.64
          5 |        971        9.71       13.35
          6 |      3,032       30.32       43.67
          7 |      2,726       27.26       70.93
          8 |      1,626       16.26       87.19
          9 |        639        6.39       93.58
         10 |        640        6.40       99.98
         99 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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