The tooltip read: “Traders and Trade Ships also return with a secondary resource. This resource is 25% the base Gold value […]”
Test 1:
Trade Ship
Base Gold Income: 69
Secondary Resource Return: 11 (15.94%)
Trader
Base Gold Income: 110
Secondary Resource Return: 27 (24.54%)
Test 2:
Trade Ship
Base Gold Income: 92
Secondary Resource Return: 15 (16.30%)
Trader
Base Gold Income: 173
Secondary Resource Return: 43 (24.85%)