Frequencies for first 10,000 rows of vin_9 variable in vehicle dataset :

      vin_9 |      Freq.     Percent        Cum.
------------+-----------------------------------
            |         47        0.47        0.47
          0 |        946        9.46        9.93
          1 |        899        8.99       18.92
          2 |        863        8.63       27.55
          3 |        859        8.59       36.14
          4 |        878        8.78       44.92
          5 |        860        8.60       53.52
          6 |        883        8.83       62.35
          7 |        863        8.63       70.98
          8 |        876        8.76       79.74
          9 |      1,192       11.92       91.66
          A |          1        0.01       91.67
          B |          2        0.02       91.69
          D |          1        0.01       91.70
          F |          1        0.01       91.71
          H |          2        0.02       91.73
          K |          1        0.01       91.74
          M |          1        0.01       91.75
          O |          3        0.03       91.78
          S |          4        0.04       91.82
          X |        812        8.12       99.94
          Y |          2        0.02       99.96
          Z |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016