The Evans Report, Palm Beach’s close analysis of the tony town’s high-end real estate market, showed sales of single-family properties hit a record low in the first half of this year. Attorney Leslie Evans listed 32 sales of single-family residences and building lots from January to June in the biannually published report. In the same period last year, 57 properties changed hands. Evans said the last six months had the lowest rate of sales since he started the report 10 years ago. He said he calculated a median sale price of $2.5 million, an average sale price of just over $2.8 million and an average percentage increase of just over 11 percent.