Lowell Company purchased equipment on January 1, 2006 for $300,000. The equipment was expected to have a useful life of 5 years, or 12,000 hours and a salvage value of $60,000. The equipment was used for 1,975 hours during 2006, 2,875 hours during 2007, 2,600 hours during 2008, 2,975 hours during 2009, and 1,575 hours during 2010. Determine the amount of depreciation expense for the years ended December 31, 2006, 2007, 2008, 2009 and 2010 by the following methods: