Frequencies for first 10,000 rows of dfage variable in natlterr2000 dataset :

     Age of |
     Father |      Freq.     Percent        Cum.
------------+-----------------------------------
         12 |          1        0.01        0.01
         14 |          1        0.01        0.02
         15 |          6        0.06        0.08
         16 |         42        0.42        0.50
         17 |        119        1.19        1.69
         18 |        245        2.45        4.14
         19 |        375        3.75        7.89
         20 |        466        4.66       12.55
         21 |        555        5.55       18.10
         22 |        536        5.36       23.46
         23 |        630        6.30       29.76
         24 |        587        5.87       35.63
         25 |        595        5.95       41.58
         26 |        597        5.97       47.55
         27 |        560        5.60       53.15
         28 |        494        4.94       58.09
         29 |        532        5.32       63.41
         30 |        406        4.06       67.47
         31 |        400        4.00       71.47
         32 |        360        3.60       75.07
         33 |        294        2.94       78.01
         34 |        298        2.98       80.99
         35 |        263        2.63       83.62
         36 |        201        2.01       85.63
         37 |        176        1.76       87.39
         38 |        141        1.41       88.80
         39 |        142        1.42       90.22
         40 |        111        1.11       91.33
         41 |        103        1.03       92.36
         42 |         90        0.90       93.26
         43 |         61        0.61       93.87
         44 |         63        0.63       94.50
         45 |         38        0.38       94.88
         46 |         36        0.36       95.24
         47 |         35        0.35       95.59
         48 |         27        0.27       95.86
         49 |         28        0.28       96.14
         50 |         12        0.12       96.26
         51 |         17        0.17       96.43
         52 |         15        0.15       96.58
         53 |         11        0.11       96.69
         54 |         13        0.13       96.82
         55 |         10        0.10       96.92
         56 |          7        0.07       96.99
         57 |          4        0.04       97.03
         58 |         10        0.10       97.13
         59 |          2        0.02       97.15
         60 |          4        0.04       97.19
         61 |          6        0.06       97.25
         65 |          3        0.03       97.28
         66 |          1        0.01       97.29
         68 |          2        0.02       97.31
         71 |          2        0.02       97.33
         72 |          1        0.01       97.34
         79 |          1        0.01       97.35
         99 |        265        2.65      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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