Glass Bottle Coffee Company is a calendar year, accrual-basis taxpayer. On October 1, 2017, Glass Bottle sold a 24-month subscription contract for $2,400. The client paid the full amount in cash. Under the contract, Glass Bottle delivers 20oz fresh, artistically roasted coffee beans to the client on the 15th of every month. The service periods covers October 1, 2017 to September 30, 2019. For tax purposes, if Glass Bottle wants to defer income recognition (to the extent allowed by tax law), how much income it should recognize in 2017? In 2018? In 2019?