Frequencies for first 10,000 rows of mpre10 variable in natl1985 dataset :

      Month |
   Prenatal |
 Care began |
  Recode 10 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,931       49.31       49.31
          2 |      2,304       23.04       72.35
          3 |      1,077       10.77       83.12
          4 |        610        6.10       89.22
          5 |        350        3.50       92.72
          6 |        285        2.85       95.57
          7 |        138        1.38       96.95
          8 |         68        0.68       97.63
          9 |        158        1.58       99.21
         10 |         79        0.79      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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