Frequencies for first 10,000 rows of dfage variable in natlterr1999 dataset :

     Age of |
     Father |      Freq.     Percent        Cum.
------------+-----------------------------------
         14 |          1        0.01        0.01
         15 |         12        0.12        0.13
         16 |         45        0.45        0.58
         17 |        120        1.20        1.78
         18 |        250        2.50        4.28
         19 |        364        3.64        7.92
         20 |        496        4.96       12.88
         21 |        522        5.22       18.10
         22 |        619        6.19       24.29
         23 |        578        5.78       30.07
         24 |        581        5.81       35.88
         25 |        551        5.51       41.39
         26 |        606        6.06       47.45
         27 |        583        5.83       53.28
         28 |        536        5.36       58.64
         29 |        456        4.56       63.20
         30 |        424        4.24       67.44
         31 |        368        3.68       71.12
         32 |        371        3.71       74.83
         33 |        314        3.14       77.97
         34 |        274        2.74       80.71
         35 |        239        2.39       83.10
         36 |        213        2.13       85.23
         37 |        167        1.67       86.90
         38 |        150        1.50       88.40
         39 |        157        1.57       89.97
         40 |        124        1.24       91.21
         41 |         94        0.94       92.15
         42 |         69        0.69       92.84
         43 |         76        0.76       93.60
         44 |         64        0.64       94.24
         45 |         44        0.44       94.68
         46 |         44        0.44       95.12
         47 |         36        0.36       95.48
         48 |         25        0.25       95.73
         49 |         27        0.27       96.00
         50 |         22        0.22       96.22
         51 |         23        0.23       96.45
         52 |         11        0.11       96.56
         53 |         15        0.15       96.71
         54 |         14        0.14       96.85
         55 |          6        0.06       96.91
         56 |          3        0.03       96.94
         57 |          8        0.08       97.02
         58 |          6        0.06       97.08
         59 |          4        0.04       97.12
         60 |          3        0.03       97.15
         61 |          3        0.03       97.18
         62 |          4        0.04       97.22
         64 |          1        0.01       97.23
         67 |          2        0.02       97.25
         68 |          2        0.02       97.27
         99 |        273        2.73      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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