Mrs. Rodriguez, a cash-basis taxpayer, owns an apartment building. Her records reflect the following information for 2012: Tenant F paid cost of floor repairs that were Mrs.Rodriguez's responsibility...............$950 Security deposits to be returned to tenants upon expiration of their leases in 2014...........$1,350 Advance rents received in December for the first six months of 2013............$3,000 What is the amount of gross rental income Mrs. Rodriguez should include in her gross income?