Frequencies for pvin_lngt variable in parkwork dataset :

 VIN length |      Freq.     Percent        Cum.
------------+-----------------------------------
          6 |          1        0.10        0.10
          7 |          1        0.10        0.20
          8 |          1        0.10        0.30
         11 |          3        0.30        0.60
         12 |          3        0.30        0.90
         13 |         10        1.00        1.90
         17 |        934       93.21       95.11
          . |         49        4.89      100.00
------------+-----------------------------------
      Total |      1,002      100.00

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