Frequencies for first 10,000 rows of dfage variable in natlterr2001 dataset :

     Age of |
     Father |      Freq.     Percent        Cum.
------------+-----------------------------------
         14 |          4        0.04        0.04
         15 |          5        0.05        0.09
         16 |         41        0.41        0.50
         17 |        127        1.27        1.77
         18 |        263        2.63        4.40
         19 |        338        3.38        7.78
         20 |        462        4.62       12.40
         21 |        551        5.51       17.91
         22 |        587        5.87       23.78
         23 |        620        6.20       29.98
         24 |        573        5.73       35.71
         25 |        546        5.46       41.17
         26 |        544        5.44       46.61
         27 |        546        5.46       52.07
         28 |        548        5.48       57.55
         29 |        519        5.19       62.74
         30 |        472        4.72       67.46
         31 |        455        4.55       72.01
         32 |        343        3.43       75.44
         33 |        306        3.06       78.50
         34 |        279        2.79       81.29
         35 |        224        2.24       83.53
         36 |        206        2.06       85.59
         37 |        180        1.80       87.39
         38 |        145        1.45       88.84
         39 |        140        1.40       90.24
         40 |        105        1.05       91.29
         41 |        109        1.09       92.38
         42 |         82        0.82       93.20
         43 |         61        0.61       93.81
         44 |         42        0.42       94.23
         45 |         53        0.53       94.76
         46 |         40        0.40       95.16
         47 |         35        0.35       95.51
         48 |         26        0.26       95.77
         49 |         23        0.23       96.00
         50 |         14        0.14       96.14
         51 |         19        0.19       96.33
         52 |         20        0.20       96.53
         53 |         12        0.12       96.65
         54 |          3        0.03       96.68
         55 |         13        0.13       96.81
         56 |         13        0.13       96.94
         57 |          2        0.02       96.96
         58 |          8        0.08       97.04
         59 |          2        0.02       97.06
         60 |          3        0.03       97.09
         61 |          5        0.05       97.14
         62 |          2        0.02       97.16
         63 |          1        0.01       97.17
         64 |          1        0.01       97.18
         65 |          1        0.01       97.19
         71 |          1        0.01       97.20
         99 |        280        2.80      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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