MARBLEHEAD – A year ago Board of Assessors Chairman John Kelley predicted Marblehead real estate values could drop as much as 5 percent by this month.Wednesday evening the town will have a chance to see if Kelley was right.That prediction came during the board’s annual discussion of property values and the real estate tax rate with selectmen. Selectmen are scheduled to meet with the Board of Assessors Wednesday evening to discuss home values and the Fiscal 2010 property tax rate.This year’s tax rate is $8.99 per $1,000 valuation, a 65-cent per $1,000 increase over the previous year. The town’s overall valuation of $5 billion included $65.8 million in new growth.However, according to the report prepared by the Board of Assessors for the selectmen in 2008, the value of the median single family home dropped from $541,000 to $519,000 in 2007 – the assessors use real estate values in place as of Jan. 1 of the current year to set next year’s tax rate. That’s a drop of $22,000 or 4.1 percent.Kelley pointed out last year the town has not overbuilt and local lenders have not granted no-verification mortgages, leaving the town in better shape than many communities nationally and even some neighboring communities in the state.”We’re in pretty good shape,” he said.Despite the drop in valuation the median single family tax bill rose last year from $4,511 in Fiscal 2008 to $4,665, an increase of $154, or 3.4 percent. In the previous two years the median assessment dropped $42,000, but the tax bill increased $312.