A project requires an investment of $$1500$ today.

It pays every $40$ days. Note: a year includes more than $40$ days.

Specifically, it pays $$200$ in $40$ days, $$400$ in $80$ days, $$500$ in $120$ days, $$450$ in $160$ days.

Suppose that you can borrow at $4\%$ p$.$a$.$ compounded annually and reinvest your cash at $8\%$ p$.$a$.$ compounded annually.

The modified IRR of this project is $\_\_\_\_\_\_\%$ per annum, compounded annually