Frequencies for pvin_4 variable in parkwork dataset :

        vin |
character(4 |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          6        0.55        0.55
          1 |          7        0.64        1.19
          2 |          5        0.46        1.65
          3 |          4        0.37        2.02
          4 |          3        0.27        2.29
          5 |          6        0.55        2.84
          6 |          1        0.09        2.93
          7 |          3        0.27        3.21
          8 |          3        0.27        3.48
          9 |         39        3.57        7.06
          A |         70        6.42       13.47
          B |         75        6.87       20.35
          C |         92        8.43       28.78
          D |         70        6.42       35.20
          E |         95        8.71       43.90
          F |         93        8.52       52.43
          G |         68        6.23       58.66
          H |         81        7.42       66.09
          J |         51        4.67       70.76
          K |         32        2.93       73.69
          L |         26        2.38       76.08
          M |         24        2.20       78.28
          N |         39        3.57       81.85
          P |         14        1.28       83.13
          R |         37        3.39       86.53
          S |         37        3.39       89.92
          T |          5        0.46       90.38
          U |          3        0.27       90.65
          V |          4        0.37       91.02
          W |         45        4.12       95.14
          X |          5        0.46       95.60
          Y |         16        1.47       97.07
          Z |         32        2.93      100.00
------------+-----------------------------------
      Total |      1,091      100.00

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