Viz Company purchased a patent on January 1, 1981 for $178,500. The patent was being amortized over its remaining life of 15 years expiring on January 1, 1996. During 1984, Viz Company determined that the economic benefits of the patent would not last longer than 10 years from the date of acquisition. What amount should be charged to patent amortization expenses for the year end December 31, 1984?