Fields laboratories holds a valuable patent 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 is as follows:

2003-2004: research conducted to develop precipitator: $384,000
jan 2005: design and construction of prototype: $87,600
march 2005: testing of models: $42,000
jan 2006: fees paid engineers and lawyers to prepare patent application: $59,500
nov 2007: engineering activity necessary to advance design to manufacturing stage: $81,500
dec 2008: legal fees paid to successfullyt defend precipitator patent: $42,000
april 2009: research aimed at modifying the design of the patented precipitator: $43,000
july 2013: legal fees pain in unsuccessful patent infringment suit: $34,000

fields assumed a useful life of 17 years when it received the initial patent. on jan 1, 2011, it revised its useful life estimate downward to 5 remaining years. amoritizations is computed for a full year if the cost is incurred prior to july 1, and no amoritization for the year if the cost is incurred after june 30. the comapny's year ends december 31.

compute the carrying value of the patent:

(a) dec 31, 2006
(b) dec 31, 2010
(c) dec 31, 2013