Below are details of Yarra Company's equipment as at 30 June 2020: Cost Accumulated depreciation Fair value less cost to dispose Discounted value in use $20,000,000 $5,400,000 $15,000,000 $16,000,000 The equipment's useful life is 10 years. Yarra Company uses the straight-line depreciation method and estimates that the residual value of the equipment is $2,000,000. As of 30 June 2020, how long has Yarra Company been using its equipment? O 2 years 1 year O 3 years O 4 years