Frequencies for pvin_2 variable in parkwork dataset :

        VIN |
Character(2 |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |          2        0.19        0.19
          0 |          9        0.85        1.03
          1 |          4        0.38        1.41
          3 |          1        0.09        1.50
          4 |          3        0.28        1.79
          5 |          2        0.19        1.97
          6 |          1        0.09        2.07
          7 |          1        0.09        2.16
          8 |          2        0.19        2.35
          9 |         37        3.48        5.83
          A |         25        2.35        8.18
          B |         60        5.64       13.82
          C |         20        1.88       15.70
          D |         31        2.91       18.61
          E |          1        0.09       18.70
          F |        238       22.37       41.07
          G |        233       21.90       62.97
          H |         90        8.46       71.43
          J |         33        3.10       74.53
          K |          2        0.19       74.72
          L |         11        1.03       75.75
          M |         38        3.57       79.32
          N |         63        5.92       85.24
          P |         10        0.94       86.18
          S |         14        1.32       87.50
          T |         81        7.61       95.11
          V |         19        1.79       96.90
          W |          3        0.28       97.18
          X |         21        1.97       99.15
          Y |          6        0.56       99.72
          Z |          3        0.28      100.00
------------+-----------------------------------
      Total |      1,064      100.00

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