Frequencies for first 10,000 rows of lmpday variable in natl1980 dataset :

   Day Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        471        4.71        4.71
          2 |        211        2.11        6.82
          3 |        235        2.35        9.17
          4 |        237        2.37       11.54
          5 |        323        3.23       14.77
          6 |        223        2.23       17.00
          7 |        236        2.36       19.36
          8 |        225        2.25       21.61
          9 |        188        1.88       23.49
         10 |        390        3.90       27.39
         11 |        200        2.00       29.39
         12 |        252        2.52       31.91
         13 |        225        2.25       34.16
         14 |        205        2.05       36.21
         15 |        752        7.52       43.73
         16 |        234        2.34       46.07
         17 |        270        2.70       48.77
         18 |        262        2.62       51.39
         19 |        192        1.92       53.31
         20 |        396        3.96       57.27
         21 |        213        2.13       59.40
         22 |        184        1.84       61.24
         23 |        237        2.37       63.61
         24 |        196        1.96       65.57
         25 |        395        3.95       69.52
         26 |        215        2.15       71.67
         27 |        217        2.17       73.84
         28 |        288        2.88       76.72
         29 |        175        1.75       78.47
         30 |        184        1.84       80.31
         31 |         73        0.73       81.04
         99 |      1,896       18.96      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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