Mortgage rates have risen to their highest level in 16 years, making it more expensive for homebuyers to finance a loan. The average rate for a 30-year fixed-rate mortgage reached 5.11% this week, according to mortgage buyer Freddie Mac. This is the highest level since April 2008, when rates were 5.17%. The increase in rates is expected to dampen home-buying interest, as higher borrowing costs make it more difficult for buyers to afford homes.