$10$ years ago, Arya took out a $30-$year, zero amortizing mortgage of $$510,000$ at the interest rate of $6\%$ p$.$a$.$ compounded monthly. There is no prepayment penalty.

Because she needs to pay for graduate school education, she decides to cash$-$out refinance.

Specifically, she refinanced into a new $27-$year, zero amortizing mortgage of $$620,000$ at the interest rate of $5\mathrm{.}5\%$ p$.$a$.$ compounded monthly.

Her average tax rate is $24\%$ and her marginal tax rate is $28\%$ this year.

The additional tax saving per year resulting from this refinancing equals $ $\_\_\_\_\_\_.$

Note: Compute the difference in tax savings before and after refinancing. If you find that she needs to pay more taxes, then provide a negative number as your answer.