Frequencies for first 10,000 rows of birmon variable in natlterr1998 dataset :

   Month of |
      Birth |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      5,248       52.48       52.48
          2 |      4,468       44.68       97.16
          3 |        284        2.84      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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