Why is the amortization for year 2015 and 2016 $12000?

Fields Laboratories holds a valuable patent (No. 758-6002-1A) on a precipitator that prevents certain types of air pollution. Fields does not manufacture or sell the products and processes it develops. Instead, it conducts research and develops products and processes which it patents, and then assigns the patents to manufacturers on a royalty basis. Occasionally it sells a patent. The history of Fields patent number 758-6002-1A is as follows Date: Activity: Cost: 2009-2011 Research conducted to develop precipitator $400,000 Jan 1. 2012 Fees paid engineers and lawyers to prepare patent application; patent granted Jan 1, 2012 200,000 Dec 31. 2014 Legal fees paid to successfully defend precipitator patent 34,000 April 1 2015 Research aimed at modifying the design of the patented precipitator 55,000 July 1 2019 Legal fees paid in unsuccessful patent infringement suit against a competitor 34,000 20 years when it received the initial precipitator Fields assumed a useful life of patent. On January 1, 2017, it revised its useful life estimate downward to remaining years. Amortization is computed for a full year if the cost is incurred prior to July 1, and no amortization for the year if the cost is incurred after June 30. The company's year ends December 31