The office vacancy rate in the battered Nashville, Tenn., market is expected to start declining this year after hitting a 14.4% peak at the end of 2009, commercial real estate professionals said. But because of the unusual nature of the downturn, the market's recovery is likely to be painfully slow. "Typically, when the real estate market gets into trouble, it's because developers built too much," said Tom Frye, managing director of CB Richard Ellis real estate in Nashville. "That's not the case here. It's lack of demand. Demand has gone down."