repayment rate vs installment rate

repayment rate and installment rate both are nouns.

Word	Noun	Adjective	Verb	Adverb
repayment rate	Yes	No	No	No
installment rate	Yes	No	No	No

As nouns, repayment rate and installment rate are synonyms defined as:

repayment rate and installment rate: the amount of money paid out per unit time

Other synonyms of repayment rate include payment rate, rate of payment.

repayment rate (noun)	installment rate (noun)
the amount of money paid out per unit time	the amount of money paid out per unit time