Chris starts to claim social security at his full retirement age (age 66). He is fully insured based on social security rule. His PIA is $2,500 per month. His wife Robin is 58 years old. She has not participated in the labor force before. They have a 30yearold son and 14 yearold daughter, who is a full-time student. Regardless of the family maximum benefit, how much of social Security benefits are available to the family?