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

   Month of |
      Birth |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,941       49.41       49.41
          2 |      4,055       40.55       89.96
          3 |      1,004       10.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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