Standard&Poor's Ratings Services assigned its 'AA-' rating, and stable outlook, to Williamson County, Texas' $83.015 million series 2004 unlimited-tax road and refunding bonds and $64.075 million series 2004A limited-tax GO refunding bonds. The rating reflects the county's: Sustained economic diversification and expansion, Successful management of growth-related pressures, and Consistently strong financial management and performance. Offsetting rating factors include the county's: Increasing and high overall net debt levels, and Significant future infrastructure needs to meet ongoing growth pressures. The county's full faith and credit pledge secures the bonds. Williamson County has experienced explosive population and property tax base growth over the past five years due to its access to Austin, Texas and the expansion of the high-tech sector. The