From your post, the bold bit. If you go to that link it shows the rates did hit 17% in Nov 1989 - Feb 1990 but through the 1970's they peaked at 10.38% in 1975 and then dropped to 9.13%in 1979 before starting to rise again through the 1980's. So they were almost half the late 80's rates in late 79.
That's why I posted the link with interest tables if you scroll down. It was a long time ago and I had to look it up.
"Then by the late 70s interest had risen to circa 17% and the house of cards fell in a heap. The same dynamic repeated itself in the late 80s/early 90s."
