Frequencies for first 10,000 rows of gestrec10 variable in natl2013 dataset :

  Gestation |
  Recode 10 |
        U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          1        0.01        0.01
          2 |         47        0.47        0.48
          3 |         90        0.90        1.38
          4 |        126        1.26        2.64
          5 |        721        7.21        9.85
          6 |      2,482       24.82       34.67
          7 |      2,611       26.11       60.78
          8 |      2,108       21.08       81.86
          9 |      1,135       11.35       93.21
         10 |        661        6.61       99.82
         99 |         18        0.18      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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