Frequencies for first 10,000 rows of dfage variable in natl2002 dataset :

     Age of |
     Father |      Freq.     Percent        Cum.
------------+-----------------------------------
         14 |          1        0.01        0.01
         15 |          1        0.01        0.02
         16 |         10        0.10        0.12
         17 |         43        0.43        0.55
         18 |         84        0.84        1.39
         19 |        156        1.56        2.95
         20 |        238        2.38        5.33
         21 |        317        3.17        8.50
         22 |        376        3.76       12.26
         23 |        391        3.91       16.17
         24 |        432        4.32       20.49
         25 |        472        4.72       25.21
         26 |        446        4.46       29.67
         27 |        432        4.32       33.99
         28 |        460        4.60       38.59
         29 |        425        4.25       42.84
         30 |        446        4.46       47.30
         31 |        446        4.46       51.76
         32 |        428        4.28       56.04
         33 |        370        3.70       59.74
         34 |        347        3.47       63.21
         35 |        295        2.95       66.16
         36 |        305        3.05       69.21
         37 |        263        2.63       71.84
         38 |        203        2.03       73.87
         39 |        225        2.25       76.12
         40 |        177        1.77       77.89
         41 |        150        1.50       79.39
         42 |        113        1.13       80.52
         43 |        101        1.01       81.53
         44 |         78        0.78       82.31
         45 |         74        0.74       83.05
         46 |         57        0.57       83.62
         47 |         45        0.45       84.07
         48 |         39        0.39       84.46
         49 |         29        0.29       84.75
         50 |         23        0.23       84.98
         51 |         11        0.11       85.09
         52 |         13        0.13       85.22
         53 |          5        0.05       85.27
         54 |          2        0.02       85.29
         55 |         10        0.10       85.39
         56 |          5        0.05       85.44
         57 |          4        0.04       85.48
         58 |          2        0.02       85.50
         59 |          3        0.03       85.53
         60 |          2        0.02       85.55
         62 |          3        0.03       85.58
         65 |          2        0.02       85.60
         67 |          1        0.01       85.61
         88 |          1        0.01       85.62
         99 |      1,438       14.38      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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