Frequencies for first 10,000 rows of mod_year variable in person dataset :

 Model Year |      Freq.     Percent        Cum.
------------+-----------------------------------
          6 |          8        0.08        0.08
         25 |          2        0.02        0.10
         40 |          3        0.03        0.13
         41 |          2        0.02        0.15
         43 |          3        0.03        0.18
         45 |          1        0.01        0.19
         46 |          9        0.09        0.28
         48 |          7        0.07        0.35
         49 |         10        0.10        0.45
         50 |          3        0.03        0.48
         51 |          7        0.07        0.55
         52 |         52        0.52        1.07
         53 |         32        0.32        1.39
         54 |         13        0.13        1.52
         55 |         51        0.51        2.03
         56 |         24        0.24        2.27
         57 |         59        0.59        2.86
         58 |         25        0.25        3.11
         59 |         51        0.51        3.62
         60 |         98        0.98        4.60
         61 |         60        0.60        5.20
         62 |        248        2.48        7.68
         63 |        238        2.38       10.06
         64 |        389        3.89       13.95
         65 |        475        4.75       18.70
         66 |        574        5.74       24.44
         67 |        578        5.78       30.22
         68 |        678        6.78       37.00
         69 |        779        7.79       44.79
         70 |        691        6.91       51.70
         71 |        743        7.43       59.13
         72 |        789        7.89       67.02
         73 |      1,002       10.02       77.04
         74 |        991        9.91       86.95
         75 |        414        4.14       91.09
         76 |         17        0.17       91.26
         99 |         82        0.82       92.08
          . |        792        7.92      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Apr 2016