Frequencies for first 10,000 rows of mage6 variable in natl1979 dataset :

     Age of |
     Mother |
   recode 6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,311       23.11       23.11
          2 |      3,617       36.17       59.28
          3 |      2,569       25.69       84.97
          4 |      1,113       11.13       96.10
          5 |        309        3.09       99.19
          6 |         81        0.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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