Frequencies for first 10,000 rows of mage15 variable in natl1987 dataset :

     Age of |
     Mother |
  recode 15 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         70        0.70        0.70
          3 |        130        1.30        2.00
          4 |        249        2.49        4.49
          5 |        382        3.82        8.31
          6 |        475        4.75       13.06
          7 |        595        5.95       19.01
          9 |        636        6.36       25.37
         10 |        612        6.12       31.49
         11 |        685        6.85       38.34
         12 |        637        6.37       44.71
         13 |        657        6.57       51.28
         14 |      2,923       29.23       80.51
         15 |      1,455       14.55       95.06
         16 |        447        4.47       99.53
         17 |         47        0.47      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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