Frequencies for first 10,000 rows of birday variable in natl1972 dataset :

 Birth Date |
      - Day |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        319        3.19        3.19
          2 |        328        3.28        6.47
          3 |        373        3.73       10.20
          4 |        359        3.59       13.79
          5 |        353        3.53       17.32
          6 |        307        3.07       20.39
          7 |        366        3.66       24.05
          8 |        344        3.44       27.49
          9 |        330        3.30       30.79
         10 |        322        3.22       34.01
         11 |        355        3.55       37.56
         12 |        316        3.16       40.72
         13 |        341        3.41       44.13
         14 |        326        3.26       47.39
         15 |        345        3.45       50.84
         16 |        339        3.39       54.23
         17 |        345        3.45       57.68
         18 |        339        3.39       61.07
         19 |        289        2.89       63.96
         20 |        320        3.20       67.16
         21 |        316        3.16       70.32
         22 |        322        3.22       73.54
         23 |        319        3.19       76.73
         24 |        349        3.49       80.22
         25 |        327        3.27       83.49
         26 |        294        2.94       86.43
         27 |        295        2.95       89.38
         28 |        337        3.37       92.75
         29 |        331        3.31       96.06
         30 |        193        1.93       97.99
         31 |        199        1.99       99.98
         99 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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