Frequencies for first 10,000 rows of monpre variable in natlterr2000 dataset :

     Detail |
   Month of |
  Pregnancy |
   Prenatal |
 Care Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         84        0.84        0.84
          1 |      1,361       13.61       14.45
          2 |      4,163       41.63       56.08
          3 |      2,144       21.44       77.52
          4 |      1,112       11.12       88.64
          5 |        558        5.58       94.22
          6 |        287        2.87       97.09
          7 |        154        1.54       98.63
          8 |         85        0.85       99.48
          9 |         22        0.22       99.70
         99 |         30        0.30      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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