Determining the age of Superia 400, based on the canister alone

I had an idea for a potential project- physically documenting film canisters to identify which era they're from. however, in the case of these fuji superia 400s, I can only guess. going from left to right my assumptions are:
20 years or so old
over ten years old
I know this one expired in 2007 and looks like the previous (minus the walmart logo)
the most recent iteration, at the most ten or so years.

So... how are my estimates? should I make this a project with more films? or does a database for this already exist?

You check the DX codes here http://industrieplus.net/dxdatabase/.

YoIaMoNwater said:

You check the DX codes here http://industrieplus.net/dxdatabase/.

Click to expand...

thank you