The following entries​ (in millions of​ dollars) are from the balance sheet of Rivendell National Bank​ (RNB): U. S. Treasury bills ​$ Demand deposits ​$ ​Mortgage-backed securities ​$ Loans from other banks ​$ ​C&I loans ​$ Discount loans ​$ NOW accounts ​$ Savings accounts ​$ Reserve deposits with Federal Reserve ​$ Cash items in the process of collection ​$ Municipal bonds ​$ Bank building ​$ If​ RNB's assets have an average duration of years and its liabilities have an average duration of ​years, what is​ RNB's duration​ gap?