Frequencies for first 10,000 rows of mage6 variable in natl1978 dataset :

     Age of |
     Mother |
   recode 6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,326       23.26       23.26
          2 |      3,599       35.99       59.25
          3 |      2,522       25.22       84.47
          4 |      1,165       11.65       96.12
          5 |        325        3.25       99.37
          6 |         63        0.63      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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