Frequencies for first 10,000 rows of dob_mm variable in natl2010 dataset :

Birth Month |
        U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        919        9.19        9.19
          2 |        809        8.09       17.28
          3 |        919        9.19       26.47
          4 |        907        9.07       35.54
          5 |        948        9.48       45.02
          6 |      1,021       10.21       55.23
          7 |      1,000       10.00       65.23
          8 |      1,032       10.32       75.55
          9 |        952        9.52       85.07
         10 |        937        9.37       94.44
         11 |        556        5.56      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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