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 = 1.6%, E(2R1) = 4.1%, E(3R1) = 6.36%, E(4R1) = 7.37%, Using the unbiased expectations theory, what is the current |(long-term) rate for four-year-maturity Treasury securities (1R4)?