Julia Wise is a social worker and her husband, Jeff Kaufman, is a software engineer. In 2013, their combined income was just under $245,000, putting them in the top 10% of US households. And yet, excluding taxes and savings, they lived on just $15,280, or 6.25% of their income.

What happened to the rest of their income, just under $100,000? They gave it to charity.