Frequencies for first 10,000 rows of mage12 variable in natl1996 dataset :

     Age of |
     Mother |
  recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         54        0.54        0.54
          3 |        116        1.16        1.70
          4 |        246        2.46        4.16
          5 |        383        3.83        7.99
          6 |        516        5.16       13.15
          7 |        608        6.08       19.23
          8 |      3,027       30.27       49.50
          9 |      2,483       24.83       74.33
         10 |      1,759       17.59       91.92
         11 |        687        6.87       98.79
         12 |        117        1.17       99.96
         13 |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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