Frequencies for first 10,000 rows of dob_mm variable in natl2004 dataset :

Birth Month |
        U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        839        8.39        8.39
          2 |        802        8.02       16.41
          3 |        936        9.36       25.77
          4 |        803        8.03       33.80
          5 |        868        8.68       42.48
          6 |        880        8.80       51.28
          7 |        857        8.57       59.85
          8 |        858        8.58       68.43
          9 |        845        8.45       76.88
         10 |        861        8.61       85.49
         11 |        785        7.85       93.34
         12 |        666        6.66      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 21 Jan 2016