Why are Allmost All of the Toyota MR2 Spyders for Sale Build in 2000, 2001, or 2002?

I'm looking for a Toyota MR2 Spyder and almost all of the advertised cars were build in either 2000, 2001, and 2002. For example, out of the 22 Spyders that are currently on GumtreeCars and carsales, only one is less than 18 years old. As I understand it, Spyders were imported into Australia until 2006. Does anyone know why?

Yeah, the pattern of the number of cars advertised on these site somewhat follow the pattern of the number of cars sold in North America.
 
Build Year  No. of Adds
2000         11
2001         6
2002         4
2003         0
2003         1
2004         0
2005         0
 

The rubber parts like hoses, window seals, etc. would probably be in better condition on the later cars. If the six speed gearbox on the later cars have closer ratio, a six would be nice, too.