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

 Model Year |      Freq.     Percent        Cum.
------------+-----------------------------------
         38 |          1        0.01        0.01
         39 |          1        0.01        0.02
         41 |          1        0.01        0.03
         44 |          1        0.01        0.04
         47 |          2        0.02        0.06
         48 |          5        0.05        0.11
         50 |          2        0.02        0.13
         51 |          2        0.02        0.15
         52 |          3        0.03        0.18
         53 |          4        0.04        0.22
         54 |          5        0.05        0.27
         55 |         12        0.12        0.39
         56 |          8        0.08        0.47
         57 |          6        0.06        0.53
         58 |          4        0.04        0.57
         59 |          9        0.09        0.66
         60 |         22        0.22        0.88
         61 |         25        0.25        1.13
         62 |         42        0.42        1.55
         63 |         56        0.56        2.11
         64 |         88        0.88        2.99
         65 |        109        1.09        4.08
         66 |        118        1.18        5.26
         67 |        125        1.25        6.51
         68 |        187        1.87        8.38
         69 |        250        2.50       10.88
         70 |        265        2.65       13.53
         71 |        339        3.39       16.92
         72 |        430        4.30       21.22
         73 |        491        4.91       26.13
         74 |        502        5.02       31.15
         75 |        425        4.25       35.40
         76 |        543        5.43       40.83
         77 |        689        6.89       47.72
         78 |        749        7.49       55.21
         79 |        771        7.71       62.92
         80 |        650        6.50       69.42
         81 |        611        6.11       75.53
         82 |        714        7.14       82.67
         83 |        677        6.77       89.44
         84 |        743        7.43       96.87
         85 |         41        0.41       97.28
         99 |        272        2.72      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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