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

 Model Year |      Freq.     Percent        Cum.
------------+-----------------------------------
         32 |          1        0.01        0.01
         38 |          2        0.02        0.03
         51 |          1        0.01        0.04
         53 |          3        0.03        0.07
         54 |          5        0.05        0.12
         55 |          8        0.08        0.20
         56 |          5        0.05        0.25
         57 |          4        0.04        0.29
         58 |          6        0.06        0.35
         59 |         15        0.15        0.50
         60 |         10        0.10        0.60
         61 |         11        0.11        0.71
         62 |         10        0.10        0.81
         63 |         19        0.19        1.00
         64 |         46        0.46        1.46
         65 |         75        0.75        2.21
         66 |         67        0.67        2.88
         67 |        112        1.12        4.00
         68 |         91        0.91        4.91
         69 |        152        1.52        6.43
         70 |        178        1.78        8.21
         71 |        180        1.80       10.01
         72 |        257        2.57       12.58
         73 |        447        4.47       17.05
         74 |        409        4.09       21.14
         75 |        303        3.03       24.17
         76 |        417        4.17       28.34
         77 |        548        5.48       33.82
         78 |        600        6.00       39.82
         79 |        599        5.99       45.81
         80 |        490        4.90       50.71
         81 |        562        5.62       56.33
         82 |        548        5.48       61.81
         83 |        481        4.81       66.62
         84 |        791        7.91       74.53
         85 |        893        8.93       83.46
         86 |        664        6.64       90.10
         87 |         22        0.22       90.32
         99 |        147        1.47       91.79
          . |        821        8.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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