Frequencies for pvin_1 variable in parkwork dataset :

        vin |
character(1 |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          8        0.70        0.70
          1 |        575       50.17       50.87
          2 |        124       10.82       61.69
          3 |         79        6.89       68.59
          4 |         62        5.41       74.00
          5 |         54        4.71       78.71
          6 |          1        0.09       78.80
          9 |         53        4.62       83.42
          A |          1        0.09       83.51
          B |          1        0.09       83.60
          C |          5        0.44       84.03
          D |          1        0.09       84.12
          F |          1        0.09       84.21
          G |          2        0.17       84.38
          J |         97        8.46       92.84
          K |         32        2.79       95.64
          R |          1        0.09       95.72
          S |          1        0.09       95.81
          T |          5        0.44       96.25
          V |          1        0.09       96.34
          W |         33        2.88       99.21
          Y |          8        0.70       99.91
          Z |          1        0.09      100.00
------------+-----------------------------------
      Total |      1,146      100.00

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