Random thought I had this morning- What car goes through generation changes the fastest or slowest?

A few random samplings that popped in my mind (birth to first of latest model)-

Chevy Corvette - 1953-2014 - 7th Generation: 8.71 years
VW Golf- 1974-2015 - 7th Generation: 5.85 years
Dodge Viper- 1992-2013 - 5th Generation: 4.2 years
BMW 3 Series- 1975-2011 - 7th Generation: 5.14 years

What are some other short or long time periods between new generations?