Frequencies for first 10,000 rows of mage15 variable in natl1978 dataset :

     Age of |
     Mother |
  recode 15 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         73        0.73        0.73
          3 |        153        1.53        2.26
          4 |        350        3.50        5.76
          5 |        504        5.04       10.80
          6 |        597        5.97       16.77
          7 |        649        6.49       23.26
          9 |        734        7.34       30.60
         10 |        742        7.42       38.02
         11 |        685        6.85       44.87
         12 |        758        7.58       52.45
         13 |        680        6.80       59.25
         14 |      2,522       25.22       84.47
         15 |      1,165       11.65       96.12
         16 |        325        3.25       99.37
         17 |         63        0.63      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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