WASHINGTON (AP) — Americans bought homes in June at the fastest rate in over eight years, pushing prices to record highs as buyer demand has eclipsed the availability of houses on the market.The National Association of Realtors said Wednesday that sales of existing homes climbed 3.2 percent last month to a seasonally adjusted annual rate of 5.49 million, the highest rate since February 2007. Sales have jumped 9.6 percent over the past 12 months, while the number of listings has risen just 0.4 percent.The median home price has climbed 6.5 percent over the past 12 months to $236,400, the highest level — unadjusted for inflation — reported by the Realtors.Home-buying has recently surged as more buyers have flooded into the real estate market. Robust hiring over the past 21 months and an economic recovery now in its sixth year have enabled more Americans to set aside money for a down payment.