Unbiased Expectations Theory Suppose that the current one-year rate (one-year spot rate) and expected one-year T-bill rates over the following three years (i.e., years 2, 3, and 4, respectively) are as follows:

₁R₁=4.90%, E(₂r₁) =5.90%, E(₃r₁) =6.40%, E(₄r₁)=6.75%

Using the unbiased expectations theory, what is the current (long-term) rate for four-year-maturity Treasury securities?