Frequencies for pvin_4 variable in parkwork dataset :

        vin |
character(4 |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |          2        0.18        0.18
          0 |         15        1.32        1.50
          1 |         12        1.06        2.56
          2 |          1        0.09        2.65
          3 |          3        0.26        2.91
          4 |          3        0.26        3.18
          5 |          9        0.79        3.97
          6 |          6        0.53        4.50
          7 |          4        0.35        4.85
          8 |          8        0.71        5.56
          9 |         26        2.29        7.86
          A |         81        7.15       15.00
          B |         88        7.77       22.77
          C |         80        7.06       29.83
          D |         84        7.41       37.25
          E |         80        7.06       44.31
          F |         72        6.35       50.66
          G |         54        4.77       55.43
          H |         96        8.47       63.90
          J |         67        5.91       69.81
          K |         31        2.74       72.55
          L |         16        1.41       73.96
          M |         24        2.12       76.08
          N |         39        3.44       79.52
          P |         22        1.94       81.47
          R |         48        4.24       85.70
          S |         26        2.29       88.00
          T |          6        0.53       88.53
          U |          4        0.35       88.88
          V |         10        0.88       89.76
          W |         44        3.88       93.65
          X |          9        0.79       94.44
          Y |         30        2.65       97.09
          Z |         33        2.91      100.00
------------+-----------------------------------
      Total |      1,133      100.00

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