Frequencies for first 10,000 rows of monpre variable in natl2000 dataset :

     Detail |
   Month of |
  Pregnancy |
   Prenatal |
 Care Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        129        1.29        1.29
          1 |      1,922       19.22       20.51
          2 |      4,439       44.39       64.90
          3 |      1,849       18.49       83.39
          4 |        697        6.97       90.36
          5 |        433        4.33       94.69
          6 |        226        2.26       96.95
          7 |        141        1.41       98.36
          8 |         94        0.94       99.30
          9 |         18        0.18       99.48
         99 |         52        0.52      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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