Myrna and Geoffrey filed a joint tax return in 2018. Their AGI was $85,000, and itemized deductions were $24,700, which included $7,000 in state income tax and no other state or local taxes. In 2019, they received a $1,800 refund of the state income taxes that they paid in 2018. The standard deduction for married filing jointly in 2018 was $24,000.
Under the tax benefit rule, what amount of the state income tax refund is included in gross income in 2019?