Following 20 years in office, Warren County Property Assessor Carolyn Miller is announcing her retirement, opening what is expected to be a hotly contested race to elect her successor.Four potential candidates have wasted no time and have already picked up their qualifying papers. “The voters of Warren County have given me several terms and I appreciate them for that, but time has come for me to retire,” Miller said. “I have enjoyed working in the office and for the people of Warren County and I wish the best to whoever the new assessor will be and will work with that person in every way for a smooth transition.”While announcing her retirement, Miller will continue to serve as assessor for almost a year as her term does not expire until Sept. 1, 2012.