Frequencies for first 10,000 rows of mage15 variable in natl1971 dataset :

     Age of |
     Mother |
  recode 15 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         54        0.54        0.54
          3 |        151        1.51        2.05
          4 |        305        3.05        5.10
          5 |        481        4.81        9.91
          6 |        607        6.07       15.98
          7 |        765        7.65       23.63
          9 |        838        8.38       32.01
         10 |        787        7.87       39.88
         11 |        757        7.57       47.45
         12 |        801        8.01       55.46
         13 |        721        7.21       62.67
         14 |      2,230       22.30       84.97
         15 |        956        9.56       94.53
         16 |        402        4.02       98.55
         17 |        145        1.45      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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