Frequencies for first 10,000 rows of mpre10 variable in natl1987 dataset :

      Month |
   Prenatal |
 Care began |
  Recode 10 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      5,226       52.26       52.26
          2 |      1,967       19.67       71.93
          3 |      1,030       10.30       82.23
          4 |        686        6.86       89.09
          5 |        330        3.30       92.39
          6 |        248        2.48       94.87
          7 |        140        1.40       96.27
          8 |         64        0.64       96.91
          9 |        213        2.13       99.04
         10 |         96        0.96      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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