Frequencies for first 10,000 rows of mpre10 variable in natl1978 dataset :

      Month |
   Prenatal |
 Care began |
  Recode 10 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,516       45.16       45.16
          2 |      2,402       24.02       69.18
          3 |      1,211       12.11       81.29
          4 |        658        6.58       87.87
          5 |        440        4.40       92.27
          6 |        332        3.32       95.59
          7 |        189        1.89       97.48
          8 |         52        0.52       98.00
          9 |        124        1.24       99.24
         10 |         76        0.76      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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