On December 1, 2019, Ral received advance rental of $27,000 from a tenant for a three-year lease commencing January 1, 2020 to cover rents for the years 2020, 2021, and 2022. In conformity with GAAP, Ral did not include any part of this rental in its income statement for the year ended December 31, 2019. What amount should Ral include in its 2019 taxable income for rent revenue?