Portugal Ability - What does it really do?

So I know Mare Clausum is listed as "Resource diversity grants twice as much Gold for Portugal in International Trade Routes"

Can anyone break down exactly what that means? Is there a quantitative way to define what resource diversity means and how does that translate into more gold per trade route?

I did not see where resources played any part in your trade route income - maybe I'm missing something obvious here.

Moderator Action: Moved to BNW.

Apologies for initially putting this in the wrong section. Hopefully someone in the BNW area will know the answer

For each resource you have in a city when choosing a trade route, you get an extra 0.5g from the route.

Portugal doubles this bonus to 1 per resource.

I haven't played Portugal yet, but from everything I've heard, it's quite good.

Awesome thanks for the reply.

Where can I see this info in-game?