In Australia in the 1980's, inflation was around 8% pa, and residential mortgage loan interest rates were around 14%.

In 2013, inflation was around 2.5% pa, and residential mortgage loan interest rates were around 4.5%.

If a person can afford constant mortgage loan payments of $**2,000** per month, how much more can they borrow when interest rates are **4.5**% pa compared with **14.0**% pa?

Give your answer as a proportional increase over the amount you could borrow when interest rates were high ##(V_\text{high rates})##, so:

###\text{Proportional increase} = \dfrac{V_\text{low rates}-V_\text{high rates}}{V_\text{high rates}} ###

Assume that:

- Interest rates are expected to be constant over the life of the loan.
- Loans are
**interest-only**and have a life of**30**years. - Mortgage loan payments are made every month in arrears and all interest rates are given as annualised percentage rates (
**APR**'s) compounding per**month**.