Sentence:  A 5 - percent royalty is paid on any production during the period the contract is in effect ; if the Government certifies that production may be possible from the property , the royalty obligation continues for the 10 - year period usually specified in the contract or until the Government 's contribution is repaid with <WSD>interest</WSD> . 
Meaning of the word marked with <WSD> tags:  a fixed charge for borrowing money; usually a percentage of the amount borrowed