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

 Model Year |      Freq.     Percent        Cum.
------------+-----------------------------------
         40 |          2        0.02        0.02
         46 |          1        0.01        0.03
         49 |          1        0.01        0.04
         51 |          4        0.04        0.08
         52 |          1        0.01        0.09
         53 |          2        0.02        0.11
         54 |          1        0.01        0.12
         55 |          3        0.03        0.15
         56 |          4        0.04        0.19
         57 |          2        0.02        0.21
         58 |          2        0.02        0.23
         59 |          2        0.02        0.25
         60 |          9        0.09        0.34
         61 |          3        0.03        0.37
         62 |          9        0.09        0.46
         63 |         21        0.21        0.67
         64 |         30        0.30        0.97
         65 |         45        0.45        1.42
         66 |         34        0.34        1.76
         67 |         49        0.49        2.25
         68 |         63        0.63        2.88
         69 |        101        1.01        3.89
         70 |         66        0.66        4.55
         71 |         87        0.87        5.42
         72 |        197        1.97        7.39
         73 |        202        2.02        9.41
         74 |        236        2.36       11.77
         75 |        202        2.02       13.79
         76 |        279        2.79       16.58
         77 |        421        4.21       20.79
         78 |        504        5.04       25.83
         79 |        551        5.51       31.34
         80 |        393        3.93       35.27
         81 |        471        4.71       39.98
         82 |        387        3.87       43.85
         83 |        453        4.53       48.38
         84 |        609        6.09       54.47
         85 |        703        7.03       61.50
         86 |        726        7.26       68.76
         87 |        766        7.66       76.42
         88 |        847        8.47       84.89
         89 |        590        5.90       90.79
         90 |         30        0.30       91.09
         99 |        168        1.68       92.77
          . |        723        7.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016