Frequencies for first 10,000 rows of mage15 variable in natl1977 dataset :

     Age of |
     Mother |
  recode 15 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         89        0.89        0.89
          3 |        158        1.58        2.47
          4 |        373        3.73        6.20
          5 |        526        5.26       11.46
          6 |        599        5.99       17.45
          7 |        771        7.71       25.16
          9 |        770        7.70       32.86
         10 |        720        7.20       40.06
         11 |        743        7.43       47.49
         12 |        708        7.08       54.57
         13 |        628        6.28       60.85
         14 |      2,505       25.05       85.90
         15 |        985        9.85       95.75
         16 |        330        3.30       99.05
         17 |         95        0.95      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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