Consider a five-person family consisting of a father, mother, twin 16-year-old sons attending high school, and an 85-year- old grandfather. The grandfather receives Social Security but has no other sources of income. The father and mother provide the majority of the grandfather's financial support because of his expensive in-home medical care. In 2017, before the change in the tax laws, what is the approximate amount of money that the parents would be able to deduct from their adjusted gross income based on their personal exemptions?