Frequencies for pvin_4 variable in parkwork dataset :

        vin |
character(4 |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          6        0.55        0.55
          1 |         10        0.92        1.48
          2 |          4        0.37        1.85
          3 |          3        0.28        2.12
          4 |          6        0.55        2.68
          5 |          6        0.55        3.23
          6 |          6        0.55        3.78
          7 |          4        0.37        4.15
          8 |          1        0.09        4.24
          9 |         28        2.58        6.83
          A |         86        7.93       14.76
          B |         88        8.12       22.88
          C |         60        5.54       28.41
          D |         84        7.75       36.16
          E |         80        7.38       43.54
          F |         72        6.64       50.18
          G |         52        4.80       54.98
          H |         81        7.47       62.45
          J |         55        5.07       67.53
          K |         33        3.04       70.57
          L |         20        1.85       72.42
          M |         31        2.86       75.28
          N |         38        3.51       78.78
          P |         19        1.75       80.54
          R |         39        3.60       84.13
          S |         27        2.49       86.62
          T |          6        0.55       87.18
          U |         21        1.94       89.11
          V |          5        0.46       89.58
          W |         45        4.15       93.73
          X |         13        1.20       94.93
          Y |         23        2.12       97.05
          Z |         32        2.95      100.00
------------+-----------------------------------
      Total |      1,084      100.00

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