Frequencies for first 10,000 rows of mage15 variable in natl1980 dataset :

     Age of |
     Mother |
  recode 15 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         62        0.62        0.62
          3 |        144        1.44        2.06
          4 |        268        2.68        4.74
          5 |        465        4.65        9.39
          6 |        541        5.41       14.80
          7 |        638        6.38       21.18
          9 |        720        7.20       28.38
         10 |        740        7.40       35.78
         11 |        771        7.71       43.49
         12 |        703        7.03       50.52
         13 |        656        6.56       57.08
         14 |      2,680       26.80       83.88
         15 |      1,207       12.07       95.95
         16 |        339        3.39       99.34
         17 |         66        0.66      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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