Hillsborough County home sales rose 20 percent from March 2008 to March 2009, the seventh month in a row in which sales have improved. Is this the beginning of the end of the housing slump? Hard to say. The Greater Tampa Association of Realtors reported 1,400 sales last month, compared with 1,162 a year earlier. Over that year, the average sales price plunged from $230,204 to $168,071. The 16,778 homes on the Realtor listings represent a 12-month supply at the current sales rate. Though a four- to six-month supply constitutes a balanced market, March's listings were the leanest since October 2006. The Realtor association compiles sales from Hillsborough and east Pasco counties. March sales totals for the entire region, including Pinellas County, are due out April 23.