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

 Model Year |      Freq.     Percent        Cum.
------------+-----------------------------------
          4 |          1        0.01        0.01
          6 |          3        0.03        0.04
          9 |          1        0.01        0.05
         12 |          1        0.01        0.06
         15 |          1        0.01        0.07
         25 |          1        0.01        0.08
         31 |          1        0.01        0.09
         40 |          2        0.02        0.11
         41 |          1        0.01        0.12
         42 |          2        0.02        0.14
         43 |          4        0.04        0.18
         45 |          2        0.02        0.20
         46 |          6        0.06        0.26
         47 |          4        0.04        0.30
         48 |         11        0.11        0.41
         49 |          9        0.09        0.50
         50 |          5        0.05        0.55
         51 |         11        0.11        0.66
         52 |         12        0.12        0.78
         53 |         25        0.25        1.03
         54 |         15        0.15        1.18
         55 |         43        0.43        1.61
         56 |         53        0.53        2.14
         57 |         61        0.61        2.75
         58 |         35        0.35        3.10
         59 |         58        0.58        3.68
         60 |         88        0.88        4.56
         61 |         83        0.83        5.39
         62 |        214        2.14        7.53
         63 |        263        2.63       10.16
         64 |        402        4.02       14.18
         65 |        509        5.09       19.27
         66 |        559        5.59       24.86
         67 |        586        5.86       30.72
         68 |        687        6.87       37.59
         69 |        767        7.67       45.26
         70 |        773        7.73       52.99
         71 |        753        7.53       60.52
         72 |        940        9.40       69.92
         73 |      1,168       11.68       81.60
         74 |      1,152       11.52       93.12
         75 |        564        5.64       98.76
         76 |         32        0.32       99.08
         99 |         92        0.92      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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