Frequencies for first 10,000 rows of mpre10 variable in natl1979 dataset :

      Month |
   Prenatal |
 Care began |
  Recode 10 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,768       47.68       47.68
          2 |      2,191       21.91       69.59
          3 |      1,144       11.44       81.03
          4 |        682        6.82       87.85
          5 |        458        4.58       92.43
          6 |        320        3.20       95.63
          7 |        158        1.58       97.21
          8 |         78        0.78       97.99
          9 |        116        1.16       99.15
         10 |         85        0.85      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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