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

 Model Year |      Freq.     Percent        Cum.
------------+-----------------------------------
         39 |         11        0.11        0.11
         47 |          1        0.01        0.12
         48 |          4        0.04        0.16
         50 |          3        0.03        0.19
         51 |          2        0.02        0.21
         52 |          1        0.01        0.22
         53 |          2        0.02        0.24
         54 |          2        0.02        0.26
         55 |          9        0.09        0.35
         56 |         11        0.11        0.46
         57 |          4        0.04        0.50
         58 |          2        0.02        0.52
         59 |          3        0.03        0.55
         60 |         12        0.12        0.67
         61 |         14        0.14        0.81
         62 |         35        0.35        1.16
         63 |         58        0.58        1.74
         64 |         56        0.56        2.30
         65 |         90        0.90        3.20
         66 |        100        1.00        4.20
         67 |        103        1.03        5.23
         68 |        149        1.49        6.72
         69 |        253        2.53        9.25
         70 |        293        2.93       12.18
         71 |        292        2.92       15.10
         72 |        401        4.01       19.11
         73 |        489        4.89       24.00
         74 |        558        5.58       29.58
         75 |        428        4.28       33.86
         76 |        517        5.17       39.03
         77 |        657        6.57       45.60
         78 |        674        6.74       52.34
         79 |        722        7.22       59.56
         80 |        585        5.85       65.41
         81 |        541        5.41       70.82
         82 |        635        6.35       77.17
         83 |        675        6.75       83.92
         84 |        643        6.43       90.35
         85 |         17        0.17       90.52
         99 |        152        1.52       92.04
          . |        796        7.96      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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