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

 Model Year |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         14        0.14        0.14
         43 |          3        0.03        0.17
         46 |          1        0.01        0.18
         47 |          2        0.02        0.20
         48 |          6        0.06        0.26
         49 |          3        0.03        0.29
         50 |          7        0.07        0.36
         51 |          4        0.04        0.40
         52 |          8        0.08        0.48
         53 |          7        0.07        0.55
         54 |         12        0.12        0.67
         55 |         11        0.11        0.78
         56 |         13        0.13        0.91
         57 |         21        0.21        1.12
         58 |          6        0.06        1.18
         59 |         15        0.15        1.33
         60 |         22        0.22        1.55
         61 |         32        0.32        1.87
         62 |         48        0.48        2.35
         63 |         72        0.72        3.07
         64 |        126        1.26        4.33
         65 |        183        1.83        6.16
         66 |        162        1.62        7.78
         67 |        196        1.96        9.74
         68 |        224        2.24       11.98
         69 |        344        3.44       15.42
         70 |        363        3.63       19.05
         71 |        419        4.19       23.24
         72 |        571        5.71       28.95
         73 |        703        7.03       35.98
         74 |        581        5.81       41.79
         75 |        549        5.49       47.28
         76 |        623        6.23       53.51
         77 |        805        8.05       61.56
         78 |        831        8.31       69.87
         79 |        913        9.13       79.00
         80 |        732        7.32       86.32
         81 |        417        4.17       90.49
         82 |         18        0.18       90.67
         99 |         58        0.58       91.25
          . |        875        8.75      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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