Frequencies for first 10,000 rows of lmpday variable in natl1996 dataset :

   Day Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        561        5.61        5.61
          2 |        248        2.48        8.09
          3 |        289        2.89       10.98
          4 |        216        2.16       13.14
          5 |        312        3.12       16.26
          6 |        209        2.09       18.35
          7 |        230        2.30       20.65
          8 |        249        2.49       23.14
          9 |        201        2.01       25.15
         10 |        371        3.71       28.86
         11 |        174        1.74       30.60
         12 |        254        2.54       33.14
         13 |        215        2.15       35.29
         14 |        200        2.00       37.29
         15 |        640        6.40       43.69
         16 |        257        2.57       46.26
         17 |        260        2.60       48.86
         18 |        227        2.27       51.13
         19 |        198        1.98       53.11
         20 |        366        3.66       56.77
         21 |        210        2.10       58.87
         22 |        219        2.19       61.06
         23 |        206        2.06       63.12
         24 |        241        2.41       65.53
         25 |        366        3.66       69.19
         26 |        222        2.22       71.41
         27 |        230        2.30       73.71
         28 |        284        2.84       76.55
         29 |        168        1.68       78.23
         30 |        253        2.53       80.76
         31 |         80        0.80       81.56
         99 |      1,844       18.44      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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