Are there several 2012 transit buses by mid-2011?

I am starting to wonder because I already saw the 2016 Honda Pilot as well as the 2016 Acura RDX on the road (aka in mid-2015). And these cars got upgraded by model year.

So, does this mean that there were several to plenty of 2012 transit buses in mid-2011?
a) yes
b)no

And do transit buses often get upgraded by model year just like cars do?
a) yes
b) no

When you answer, can you give me an explanation?

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