Frequencies for first 10,000 rows of lmpday variable in natlterr1998 dataset :

   Day Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        316        3.16        3.16
          2 |        305        3.05        6.21
          3 |        315        3.15        9.36
          4 |        309        3.09       12.45
          5 |        468        4.68       17.13
          6 |        296        2.96       20.09
          7 |        307        3.07       23.16
          8 |        304        3.04       26.20
          9 |        277        2.77       28.97
         10 |        480        4.80       33.77
         11 |        258        2.58       36.35
         12 |        353        3.53       39.88
         13 |        291        2.91       42.79
         14 |        325        3.25       46.04
         15 |        548        5.48       51.52
         16 |        318        3.18       54.70
         17 |        302        3.02       57.72
         18 |        321        3.21       60.93
         19 |        250        2.50       63.43
         20 |        462        4.62       68.05
         21 |        264        2.64       70.69
         22 |        267        2.67       73.36
         23 |        301        3.01       76.37
         24 |        317        3.17       79.54
         25 |        361        3.61       83.15
         26 |        265        2.65       85.80
         27 |        299        2.99       88.79
         28 |        337        3.37       92.16
         29 |        247        2.47       94.63
         30 |        278        2.78       97.41
         31 |         66        0.66       98.07
         99 |        193        1.93      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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