Frequencies for pvin_6 variable in parkwork dataset :

        vin |
character(6 |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         45        4.13        4.13
          1 |        236       21.67       25.80
          2 |        116       10.65       36.46
          3 |        121       11.11       47.57
          4 |         95        8.72       56.29
          5 |        137       12.58       68.87
          6 |         70        6.43       75.30
          7 |         45        4.13       79.43
          8 |         36        3.31       82.74
          9 |         38        3.49       86.23
          A |         33        3.03       89.26
          B |         18        1.65       90.91
          C |          9        0.83       91.74
          E |          2        0.18       91.92
          F |         11        1.01       92.93
          G |          5        0.46       93.39
          H |          5        0.46       93.85
          J |          1        0.09       93.94
          K |          1        0.09       94.03
          L |          9        0.83       94.86
          N |          1        0.09       94.95
          P |          4        0.37       95.32
          R |          3        0.28       95.59
          S |         13        1.19       96.79
          T |          6        0.55       97.34
          U |          4        0.37       97.70
          V |          4        0.37       98.07
          W |          8        0.73       98.81
          X |          6        0.55       99.36
          Y |          1        0.09       99.45
          Z |          6        0.55      100.00
------------+-----------------------------------
      Total |      1,089      100.00

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