Frequencies for pvin_6 variable in parkwork dataset :

        VIN |
Character(6 |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |          2        0.19        0.19
          0 |         49        4.61        4.79
          1 |        231       21.71       26.50
          2 |        112       10.53       37.03
          3 |        101        9.49       46.52
          4 |         93        8.74       55.26
          5 |        167       15.70       70.96
          6 |         73        6.86       77.82
          7 |         50        4.70       82.52
          8 |         29        2.73       85.24
          9 |         52        4.89       90.13
          A |         33        3.10       93.23
          B |         22        2.07       95.30
          C |          7        0.66       95.96
          D |          5        0.47       96.43
          E |          2        0.19       96.62
          F |          6        0.56       97.18
          G |          1        0.09       97.27
          H |          3        0.28       97.56
          J |          2        0.19       97.74
          L |          4        0.38       98.12
          P |          1        0.09       98.21
          R |          4        0.38       98.59
          S |          6        0.56       99.15
          T |          2        0.19       99.34
          U |          4        0.38       99.72
          V |          1        0.09       99.81
          X |          1        0.09       99.91
          Z |          1        0.09      100.00
------------+-----------------------------------
      Total |      1,064      100.00

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