LRF Corporation purchased a patent for $12,868 on the last day of month 4, year 1. It had a useful life of 16 years. On January 1, year 4, LRF spent $5,173 to successfully defend the patent in a lawsuit. LRF feels that as of that date, the remaining useful life is 7 years. What amount should be reported for patent amortization expense for year 4?