Frequencies for first 10,000 rows of gestat10 variable in natl1992 dataset :

  Gestation |
  Recode 10 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          3        0.03        0.03
          2 |         85        0.85        0.88
          3 |        147        1.47        2.35
          4 |        676        6.76        9.11
          5 |        443        4.43       13.54
          6 |      4,098       40.98       54.52
          7 |      2,144       21.44       75.96
          8 |      1,272       12.72       88.68
          9 |      1,125       11.25       99.93
         10 |          7        0.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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