Frequencies for first 10,000 rows of lmpday variable in natl1998 dataset :

   Day Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        627        6.27        6.27
          2 |        199        1.99        8.26
          3 |        253        2.53       10.79
          4 |        246        2.46       13.25
          5 |        345        3.45       16.70
          6 |        246        2.46       19.16
          7 |        276        2.76       21.92
          8 |        227        2.27       24.19
          9 |        226        2.26       26.45
         10 |        360        3.60       30.05
         11 |        209        2.09       32.14
         12 |        272        2.72       34.86
         13 |        214        2.14       37.00
         14 |        274        2.74       39.74
         15 |        737        7.37       47.11
         16 |        270        2.70       49.81
         17 |        228        2.28       52.09
         18 |        260        2.60       54.69
         19 |        229        2.29       56.98
         20 |        395        3.95       60.93
         21 |        260        2.60       63.53
         22 |        196        1.96       65.49
         23 |        246        2.46       67.95
         24 |        234        2.34       70.29
         25 |        357        3.57       73.86
         26 |        230        2.30       76.16
         27 |        207        2.07       78.23
         28 |        315        3.15       81.38
         29 |        168        1.68       83.06
         30 |        302        3.02       86.08
         31 |         77        0.77       86.85
         99 |      1,315       13.15      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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