Frequencies for first 10,000 rows of dfage variable in natlterr1995 dataset :

     Age of |
     Father |      Freq.     Percent        Cum.
------------+-----------------------------------
         12 |          1        0.01        0.01
         14 |          3        0.03        0.04
         15 |         13        0.13        0.17
         16 |         62        0.62        0.79
         17 |        132        1.32        2.11
         18 |        251        2.51        4.62
         19 |        367        3.67        8.29
         20 |        525        5.25       13.54
         21 |        584        5.84       19.38
         22 |        607        6.07       25.45
         23 |        566        5.66       31.11
         24 |        614        6.14       37.25
         25 |        573        5.73       42.98
         26 |        541        5.41       48.39
         27 |        519        5.19       53.58
         28 |        508        5.08       58.66
         29 |        485        4.85       63.51
         30 |        439        4.39       67.90
         31 |        402        4.02       71.92
         32 |        347        3.47       75.39
         33 |        326        3.26       78.65
         34 |        312        3.12       81.77
         35 |        241        2.41       84.18
         36 |        211        2.11       86.29
         37 |        150        1.50       87.79
         38 |        143        1.43       89.22
         39 |        120        1.20       90.42
         40 |        121        1.21       91.63
         41 |        100        1.00       92.63
         42 |         68        0.68       93.31
         43 |         74        0.74       94.05
         44 |         57        0.57       94.62
         45 |         48        0.48       95.10
         46 |         39        0.39       95.49
         47 |         37        0.37       95.86
         48 |         26        0.26       96.12
         49 |         32        0.32       96.44
         50 |         22        0.22       96.66
         51 |         17        0.17       96.83
         52 |         13        0.13       96.96
         53 |         11        0.11       97.07
         54 |         14        0.14       97.21
         55 |          8        0.08       97.29
         56 |         11        0.11       97.40
         57 |          6        0.06       97.46
         58 |          4        0.04       97.50
         59 |          2        0.02       97.52
         60 |          5        0.05       97.57
         61 |          2        0.02       97.59
         63 |          1        0.01       97.60
         64 |          2        0.02       97.62
         65 |          2        0.02       97.64
         66 |          4        0.04       97.68
         67 |          1        0.01       97.69
         69 |          1        0.01       97.70
         74 |          1        0.01       97.71
         77 |          1        0.01       97.72
         99 |        228        2.28      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015