Frequencies for first 10,000 rows of birday variable in natl1979 dataset :

 Birth Date |
      - Day |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        349        3.49        3.49
          2 |        417        4.17        7.66
          3 |        331        3.31       10.97
          4 |        385        3.85       14.82
          5 |        399        3.99       18.81
          6 |        391        3.91       22.72
          7 |        338        3.38       26.10
          8 |        390        3.90       30.00
          9 |        355        3.55       33.55
         10 |        356        3.56       37.11
         11 |        327        3.27       40.38
         12 |        395        3.95       44.33
         13 |        350        3.50       47.83
         14 |        333        3.33       51.16
         15 |        372        3.72       54.88
         16 |        355        3.55       58.43
         17 |        310        3.10       61.53
         18 |        321        3.21       64.74
         19 |        390        3.90       68.64
         20 |        323        3.23       71.87
         21 |        279        2.79       74.66
         22 |        324        3.24       77.90
         23 |        318        3.18       81.08
         24 |        260        2.60       83.68
         25 |        271        2.71       86.39
         26 |        268        2.68       89.07
         27 |        255        2.55       91.62
         28 |        263        2.63       94.25
         29 |        190        1.90       96.15
         30 |        195        1.95       98.10
         31 |        190        1.90      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016