The following information is available for Paragon as of November 30, 20X5. Property, plant and equipment Land $27,500 Building $36,000 Accumulated depreciation (13,500) Paragon's building is being depreciated using the straight-line method. The building has a 20-year estimated useful life and an estimated salvage value of $6,000. The number of years the building has been depreciated by Paragon as of November 30, 20X5 is