Frequencies for first 10,000 rows of lmpday variable in natlterr1996 dataset :

   Day Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        324        3.24        3.24
          2 |        273        2.73        5.97
          3 |        323        3.23        9.20
          4 |        283        2.83       12.03
          5 |        433        4.33       16.36
          6 |        293        2.93       19.29
          7 |        339        3.39       22.68
          8 |        306        3.06       25.74
          9 |        288        2.88       28.62
         10 |        446        4.46       33.08
         11 |        267        2.67       35.75
         12 |        294        2.94       38.69
         13 |        309        3.09       41.78
         14 |        340        3.40       45.18
         15 |        559        5.59       50.77
         16 |        295        2.95       53.72
         17 |        336        3.36       57.08
         18 |        362        3.62       60.70
         19 |        259        2.59       63.29
         20 |        438        4.38       67.67
         21 |        279        2.79       70.46
         22 |        266        2.66       73.12
         23 |        305        3.05       76.17
         24 |        284        2.84       79.01
         25 |        388        3.88       82.89
         26 |        305        3.05       85.94
         27 |        288        2.88       88.82
         28 |        317        3.17       91.99
         29 |        252        2.52       94.51
         30 |        295        2.95       97.46
         31 |         59        0.59       98.05
         99 |        195        1.95      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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