A company is considering purchasing equipment costing $85,000. The equipment is expected to reduce costs from year 1 to 4 by $20,000, year 5 to 8 by $10,000, and in year 9 by $1,000. In year 9, the equipment can be sold at a salvage value of $15,000. Calculate the internal rate of return (IRR) for this proposal.

The internal rate of return is _____________%