Andrew M. Raim^[ [email protected], Center for Statistical Research & Methodology, U.S. Census Bureau, Washington, DC, 20233, U.S.A. Disclaimer: This document is released to inform interested parties of ongoing research and to encourage discussion of work in progress. Any views expressed are those of the authors and not those of the U.S. Census Bureau. ], Kimberly F. Sellers^[ [email protected], Center for Statistical Research & Methodology, U.S. Census Bureau and Department of Mathematics and Statistics, Georgetown University, Washington, DC, 20057, U.S.A. ]