Age of cars

This must be some kind ritual.

Let's see - twelve in total, deducting one Yankee and one Jap for
daily use, deducting one Russian as a parts source to the other
running Russian, but including one Jap under surgery along with
two concourse Brits, and five other Japs, all the Japs being
vintage, of which 2 are as original.

Applying the proper weighting we have:

Two hundred and ninety seven twelve divided by nine equals thirty
one point six.

There, I've done my bit, I think.

Mike
AN5 10426 etc.