Frequencies for pvin_6 variable in parkwork dataset :

        vin |
character(6 |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         49        4.49        4.49
          1 |        223       20.44       24.93
          2 |        128       11.73       36.66
          3 |        106        9.72       46.38
          4 |        107        9.81       56.19
          5 |        157       14.39       70.58
          6 |         73        6.69       77.27
          7 |         37        3.39       80.66
          8 |         29        2.66       83.32
          9 |         57        5.22       88.54
          A |         35        3.21       91.75
          B |         13        1.19       92.94
          C |          9        0.82       93.77
          D |          1        0.09       93.86
          E |          3        0.27       94.13
          F |          4        0.37       94.50
          G |          2        0.18       94.68
          H |          6        0.55       95.23
          J |          3        0.27       95.51
          L |          8        0.73       96.24
          M |          2        0.18       96.43
          N |          2        0.18       96.61
          P |          5        0.46       97.07
          R |          2        0.18       97.25
          S |          8        0.73       97.98
          T |          3        0.27       98.26
          U |          2        0.18       98.44
          V |          1        0.09       98.53
          W |          4        0.37       98.90
          X |          3        0.27       99.18
          Y |          3        0.27       99.45
          Z |          6        0.55      100.00
------------+-----------------------------------
      Total |      1,091      100.00

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