A firm is planning to improve its infrastructure, and currently there are two projects considered for this purpose: Project X and Project Y$.$ Project X has an initial cost of $$84,933\mathrm{.}61$ and is expected to generate annual cash flows of $$8,000$ for the next $20$ years. Project Y has an initial cost of $$49,000\mathrm{.}00$ and is expected to generate annual cash flows of $$4,100$ for the next $20$ years. What is the crossover rate?