Trade Good Upgrading
Many low-quality trade goods can upgrade to better ones when their province is developed enough.
This will take less time the more developed the province is, and starts at either 15 dev and 3 buildings in the province, or at 30 dev, and takes a mean of 200 years reduced by increasing development and building count.
List of upgradeable trade goods:
Fish
Slaves
Grain
Wool
Naval Supplies
Tropical Wood
Incense
Wine
Salt
Spices
Livestock
Fur
Tea
Coffee
Cotton
List of possible resulting trade goods:
Cloth (Cotton and Wool++++++, Fur+)
Glass(Wine++, Salt+)
Paper(Tropical Wood+, Naval Supplies++)
Chinaware (only for East Asia and SEA, Tea++, Coffee+)
Silk (Christian—-, Hindu++, Persian+, Byzantine+)
Additionally, cotton has been nerfed slightly and chinaware and glass buffed slightly so that the upgrades are actually upgrades.
