Frequencies for first 10,000 rows of mage15 variable in natl1981 dataset :

     Age of |
     Mother |
  recode 15 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         44        0.44        0.44
          3 |        124        1.24        1.68
          4 |        290        2.90        4.58
          5 |        411        4.11        8.69
          6 |        529        5.29       13.98
          7 |        637        6.37       20.35
          9 |        698        6.98       27.33
         10 |        727        7.27       34.60
         11 |        719        7.19       41.79
         12 |        723        7.23       49.02
         13 |        670        6.70       55.72
         14 |      2,817       28.17       83.89
         15 |      1,215       12.15       96.04
         16 |        326        3.26       99.30
         17 |         70        0.70      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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