Frequencies for first 10,000 rows of mage12 variable in natlterr1998 dataset :

     Age of |
     Mother |
  recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         58        0.58        0.58
          3 |        155        1.55        2.13
          4 |        272        2.72        4.85
          5 |        416        4.16        9.01
          6 |        549        5.49       14.50
          7 |        603        6.03       20.53
          8 |      3,178       31.78       52.31
          9 |      2,483       24.83       77.14
         10 |      1,576       15.76       92.90
         11 |        589        5.89       98.79
         12 |        115        1.15       99.94
         13 |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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