Frequencies for pvin_11 variable in parkwork dataset :

        VIN |
Character(1 |
         1) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |          9        0.85        0.85
          0 |         34        3.20        4.04
          1 |         38        3.57        7.61
          2 |         15        1.41        9.02
          3 |          6        0.56        9.59
          4 |         20        1.88       11.47
          5 |         19        1.79       13.25
          6 |         20        1.88       15.13
          7 |         19        1.79       16.92
          8 |         12        1.13       18.05
          9 |         50        4.70       22.74
          A |         49        4.61       27.35
          B |         40        3.76       31.11
          C |         82        7.71       38.82
          D |         29        2.73       41.54
          E |         49        4.61       46.15
          F |         42        3.95       50.09
          G |         12        1.13       51.22
          H |         60        5.64       56.86
          J |         36        3.38       60.24
          K |         33        3.10       63.35
          L |         47        4.42       67.76
          M |         26        2.44       70.21
          N |         42        3.95       74.15
          P |         22        2.07       76.22
          R |         36        3.38       79.61
          S |         33        3.10       82.71
          T |         15        1.41       84.12
          U |         56        5.26       89.38
          V |          9        0.85       90.23
          W |         26        2.44       92.67
          X |         24        2.26       94.92
          Y |          9        0.85       95.77
          Z |         45        4.23      100.00
------------+-----------------------------------
      Total |      1,064      100.00

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