Douglas County saw some movement in its top 10 most valuable properties during 2012.Assessor Doug Sonnemann said the construction of the new Walmart increased the value of that company's property in Douglas County to $8.8 million. That moved it into the top 10 for the first time.The purchase of two Lake Tahoe residential properties bumped Bently Family Ltd., up from seventh to sixth.Sonnemann said the market during the year seemed to be better in the first half than in the second."The market is still trying to find its feet," he said.The number of homes sold the same year as they …