Frequencies for first 10,000 rows of mage7 variable in natl1970 dataset :

     Age of |
     Mother |
   recode 7 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         57        0.57        0.57
          2 |      2,346       23.46       24.03
          3 |      3,790       37.90       61.93
          4 |      2,200       22.00       83.93
          5 |        980        9.80       93.73
          6 |        479        4.79       98.52
          7 |        148        1.48      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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