Highland Inc. holds 70% of the common shares of Sissy Inc. On January 1, 20X5, Sissy sold equipment to Highland for $17,500. Sissy purchased this equipment from an independent non-associate for $25,000 on January 1, 20X1 and it has a net book value of $15,000 on January 1, 20X5. The equipment has a useful life of 10 years. The unrealized gain eliminated on consolidation in 20X5 is $2,500. When will this unrealized gain be fully realized from a consolidation perspective?