Mary Beth owns a rental house. Her current tenant, Carl signed a two year lease and moved into the house in January of last year. At that time, Carl paid Mary Beth $1,600 for first months rent, $1,600 for last months rent, and $1,600 as a security deposit. Carl paid the $1,600 monthly rent in cash on the first of each month during the year, except in November when he replaced the water heater in exchange for his rent. The water heater would have cost Mary Beth $1,100 to purchase and install. How much rental income must Mary Beth report for last year?