Frequencies for first 10,000 rows of mage12 variable in natl2001 dataset :

     Age of |
     Mother |
  Recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         34        0.34        0.34
          3 |         77        0.77        1.11
          4 |        156        1.56        2.67
          5 |        314        3.14        5.81
          6 |        423        4.23       10.04
          7 |        566        5.66       15.70
          8 |      3,196       31.96       47.66
          9 |      2,644       26.44       74.10
         10 |      1,708       17.08       91.18
         11 |        744        7.44       98.62
         12 |        130        1.30       99.92
         13 |          8        0.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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