Frequencies for first 10,000 rows of lmpday variable in natl1990 dataset :

   Day Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        525        5.25        5.25
          2 |        180        1.80        7.05
          3 |        249        2.49        9.54
          4 |        221        2.21       11.75
          5 |        360        3.60       15.35
          6 |        259        2.59       17.94
          7 |        234        2.34       20.28
          8 |        238        2.38       22.66
          9 |        189        1.89       24.55
         10 |        387        3.87       28.42
         11 |        177        1.77       30.19
         12 |        303        3.03       33.22
         13 |        202        2.02       35.24
         14 |        264        2.64       37.88
         15 |        603        6.03       43.91
         16 |        231        2.31       46.22
         17 |        242        2.42       48.64
         18 |        243        2.43       51.07
         19 |        210        2.10       53.17
         20 |        371        3.71       56.88
         21 |        231        2.31       59.19
         22 |        241        2.41       61.60
         23 |        235        2.35       63.95
         24 |        213        2.13       66.08
         25 |        344        3.44       69.52
         26 |        211        2.11       71.63
         27 |        202        2.02       73.65
         28 |        313        3.13       76.78
         29 |        164        1.64       78.42
         30 |        182        1.82       80.24
         31 |         70        0.70       80.94
         99 |      1,906       19.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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