Frequencies for first 10,000 rows of birmon variable in natl1994 dataset :

   Month of |
      Birth |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      5,101       51.01       51.01
          2 |      4,000       40.00       91.01
          3 |        899        8.99      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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