Frequencies for first 10,000 rows of lmpday variable in natl1978 dataset :

   Day Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        523        5.23        5.23
          2 |        200        2.00        7.23
          3 |        232        2.32        9.55
          4 |        262        2.62       12.17
          5 |        390        3.90       16.07
          6 |        232        2.32       18.39
          7 |        220        2.20       20.59
          8 |        227        2.27       22.86
          9 |        184        1.84       24.70
         10 |        386        3.86       28.56
         11 |        190        1.90       30.46
         12 |        235        2.35       32.81
         13 |        197        1.97       34.78
         14 |        203        2.03       36.81
         15 |        736        7.36       44.17
         16 |        232        2.32       46.49
         17 |        228        2.28       48.77
         18 |        258        2.58       51.35
         19 |        199        1.99       53.34
         20 |        384        3.84       57.18
         21 |        216        2.16       59.34
         22 |        181        1.81       61.15
         23 |        226        2.26       63.41
         24 |        216        2.16       65.57
         25 |        357        3.57       69.14
         26 |        201        2.01       71.15
         27 |        195        1.95       73.10
         28 |        305        3.05       76.15
         29 |        146        1.46       77.61
         30 |        192        1.92       79.53
         31 |         79        0.79       80.32
         99 |      1,968       19.68      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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