You said "interest rate was 30% in the 80s"...any reasonable person would assume you're talking about some kind of a average rate for the decade or a base rate like Fed prime. Nobody is going to assume you were talking about your family's personal rate from specifically the year of 1980...ugh.
My parents could only get their modest home for their 6 kids at 30% when they moved in 1980.
Any reasonable person would read what I wrote and not add or subtract words arbitrarily.