Frequencies for pvin_bt variable in parkwork dataset :

   vin body |
       type |      Freq.     Percent        Cum.
------------+-----------------------------------
            |         59        5.41        5.41
         2D |          5        0.46        5.87
         2H |         19        1.74        7.61
         2T |          2        0.18        7.79
         2W |          6        0.55        8.34
         3C |          7        0.64        8.98
         3P |          1        0.09        9.07
         4B |          1        0.09        9.17
         4C |         44        4.03       13.20
         4D |        292       26.76       39.96
         4H |         14        1.28       41.25
         4W |         30        2.75       44.00
         BU |          4        0.37       44.36
         CB |         27        2.47       46.84
         CC |         42        3.85       50.69
         CG |         11        1.01       51.70
         CH |          3        0.27       51.97
         CP |         45        4.12       56.10
         CV |         11        1.01       57.10
         CW |         55        5.04       62.14
         EC |          3        0.27       62.42
         ES |         32        2.93       65.35
         MH |          4        0.37       65.72
         PC |         29        2.66       68.38
         PK |         69        6.32       74.70
         RD |          2        0.18       74.89
         RS |          6        0.55       75.44
         SP |          1        0.09       75.53
         SV |         35        3.21       78.74
         SW |         10        0.92       79.65
         TB |          7        0.64       80.29
         TR |         74        6.78       87.08
         UT |        135       12.37       99.45
         YY |          6        0.55      100.00
------------+-----------------------------------
      Total |      1,091      100.00

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