Axo Mirth Company paid $24 million to purchase a drug patent on April 1, 2013. At the date of purchase, the patent remained valid for another 12 years. In 2015, the company spent $4 million to successfully defend the patent, with the case closed on September 30, 2015. The company has a December 31 year-end.

Required:
Taking account of partial years, compute the amount of patent amortization for 2013, 2014, 2015, and 2016.