Frequencies for first 10,000 rows of precare variable in natlterr2009 dataset :

      Month |
   Prenatal |
 Care Began |
        RFP |
 668=f_mpcb |
          R |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         18        0.18        0.18
          1 |        538        5.38        5.56
          2 |      2,705       27.05       32.61
          3 |      2,408       24.08       56.69
          4 |        972        9.72       66.41
          5 |        457        4.57       70.98
          6 |        237        2.37       73.35
          7 |         99        0.99       74.34
          8 |         69        0.69       75.03
          9 |         16        0.16       75.19
         99 |         32        0.32       75.51
          . |      2,449       24.49      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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