Frequencies for first 10,000 rows of mpre5 variable in linkco1991us_num dataset :

      Month |
   Prenatal |
 Care Began |
   Recode 5 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      6,380       63.80       63.80
          2 |      1,936       19.36       83.16
          3 |        397        3.97       87.13
          4 |        794        7.94       95.07
          5 |        493        4.93      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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