18) On January 1 of Year 1, Cong Express Airways issued $3,500,000 of 7%, bonds, that pay interest semiannually on January 1 and July 1. The bond issue price is $3,197,389 and the market rate of interest for similar bonds is 8%. The bond premium or discount is being amortized using the straight-line method at a rate of $10,087 every six months. The life of these bonds is:

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