Frequencies for first 10,000 rows of mage12 variable in natl1975 dataset :

     Age of |
     Mother |
  recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         69        0.69        0.69
          3 |        198        1.98        2.67
          4 |        409        4.09        6.76
          5 |        551        5.51       12.27
          6 |        658        6.58       18.85
          7 |        764        7.64       26.49
          8 |      3,575       35.75       62.24
          9 |      2,441       24.41       86.65
         10 |        931        9.31       95.96
         11 |        314        3.14       99.10
         12 |         85        0.85       99.95
         13 |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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