If the inflation premium is 3.5% per year, the liquidity premium is 0.4% per year, the maturity premium is 1.2% per year, the real interest rate is 3.1% per year, and the default premium is 2.5% per year, what is the annual risk-free interest rate? 1) 7.0% 2) 6.2% 03) 5.7% 4) 6.6% 5) 7.8%