Frequencies for first 10,000 rows of birmon variable in natl2001 dataset :

   Month of |
      Birth |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      5,288       52.88       52.88
          2 |      4,405       44.05       96.93
          3 |        307        3.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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