Bay Area home sales for July fell to the lowest level in 15 years and the year-over-year decline is the largest for any month since May 2008. MDA DataQuick said 6,773 homes were sold during the month across the nine-county area of central California, which is down 22.8% from a year ago and 19.1% lower than June. The San Diego real estate research firm said the expiration of the federal homebuyer tax credit hampered sales for the month. But the July numbers haven’t been this weak since 6,666 homes sold in 1995 and are off 28.8% from 1988, when DataQuick began collecting the data. “There’s been a pause in the market,” MDA DataQuick president John Walsh said. “Some potential buyers – including those who held off until the tax credits expired – will take their time to assess market conditions, searching for signs of renewed price cuts. Depending on the economy and other factors, that might be what some of them find, especially in areas with a growing number of homes for sale – particularly distressed properties.” Sales of foreclosed properties accounted for 26.1% of July’s total. That number is up slightly from 25.6% in June yet down from 33.6% a year ago. DataQuick said foreclosure sales peaked in February at 52% of all sales that month. Some 10.3% of all new loans in July were adjustable-rate mortgages, down from 12.2% last month but up from 6.6% a year ago. The average monthly ARM rate over the last decade is nearly 50% and ARMs hit a low of 3% in January 2009, according to DataQuick. FHA loans accounted for 23.3% of Bay Area purchase lending last month, down from 25% percent in June and from 24.1% a year ago. Two years ago FHA loans were just 12.7% of purchase mortgages. Write to Jason Philyaw.