Frequencies for first 10,000 rows of gestat10 variable in natl1982 dataset :

  Gestation |
  Recode 10 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          5        0.05        0.05
          2 |         74        0.74        0.79
          3 |        134        1.34        2.13
          4 |        527        5.27        7.40
          5 |        333        3.33       10.73
          6 |      3,537       35.37       46.10
          7 |      2,055       20.55       66.65
          8 |      1,478       14.78       81.43
          9 |      1,660       16.60       98.03
         10 |        197        1.97      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016