Need help in supply contracts (Little Upsilon)

i have a coal company in ceo to transfering coal to gold companys.my question is how should i maintain the supply contracts in percentage in order to keep the company going in the right direction with out having to buy supplies on the world market.at the moment it is 50% transfer in the contracts.should i increase to 75% or more?thank you once again.

The easiest way would be to contract over the local market. Just offer your coal company's production and tell your gold companies to accept; they'll accept 100% (providing enough is offered).

Unless that's not what you were asking...

no i'm talking about transfering coal to the gold company for the monthly use.at the moment it is 50% of coal to be transfer to the gold company which 100,000 tons of coal.should it be 150,000 or 200,000 of tons each month contracts?