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

 MODEL YEAR |      Freq.     Percent        Cum.
------------+-----------------------------------
         54 |          2        0.02        0.02
         55 |          1        0.01        0.03
         56 |          1        0.01        0.04
         57 |          1        0.01        0.05
         58 |          5        0.05        0.10
         59 |          5        0.05        0.15
         61 |          2        0.02        0.17
         62 |          9        0.09        0.26
         63 |         14        0.14        0.40
         64 |         14        0.14        0.54
         65 |         34        0.34        0.88
         66 |         33        0.33        1.21
         67 |         23        0.23        1.44
         68 |         56        0.56        2.00
         69 |         56        0.56        2.56
         70 |         69        0.69        3.25
         71 |         63        0.63        3.88
         72 |         97        0.97        4.85
         73 |        122        1.22        6.07
         74 |        123        1.23        7.30
         75 |        110        1.10        8.40
         76 |        194        1.94       10.34
         77 |        220        2.20       12.54
         78 |        399        3.99       16.53
         79 |        466        4.66       21.19
         80 |        310        3.10       24.29
         81 |        309        3.09       27.38
         82 |        415        4.15       31.53
         83 |        437        4.37       35.90
         84 |        542        5.42       41.32
         85 |        642        6.42       47.74
         86 |        663        6.63       54.37
         87 |        533        5.33       59.70
         88 |        623        6.23       65.93
         89 |        709        7.09       73.02
         90 |        585        5.85       78.87
         91 |        707        7.07       85.94
         92 |        480        4.80       90.74
         93 |         43        0.43       91.17
         99 |        140        1.40       92.57
          . |        743        7.43      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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