Frequencies for pvin_7 variable in parkwork dataset :

        vin |
character(7 |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         43        3.75        3.75
          1 |        106        9.25       13.00
          2 |        134       11.69       24.69
          3 |        105        9.16       33.86
          4 |        102        8.90       42.76
          5 |         57        4.97       47.73
          6 |         97        8.46       56.20
          7 |         36        3.14       59.34
          8 |        102        8.90       68.24
          9 |        105        9.16       77.40
          A |         45        3.93       81.33
          B |         22        1.92       83.25
          C |         35        3.05       86.30
          D |         24        2.09       88.39
          E |         40        3.49       91.88
          F |         15        1.31       93.19
          G |          9        0.79       93.98
          H |         23        2.01       95.99
          J |         16        1.40       97.38
          K |          4        0.35       97.73
          L |          1        0.09       97.82
          M |          1        0.09       97.91
          N |          3        0.26       98.17
          P |          4        0.35       98.52
          R |          1        0.09       98.60
          S |          4        0.35       98.95
          T |          4        0.35       99.30
          W |          1        0.09       99.39
          X |          2        0.17       99.56
          Y |          3        0.26       99.83
          Z |          2        0.17      100.00
------------+-----------------------------------
      Total |      1,146      100.00

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