The Fourth Report uses a new procedure to estimate percentiles when the percentile estimate falls on a value that is repeated multiple times (e.g., five results that all have the value 90.1). Percentiles for all three NHANES survey periods (1999-2000, 2001-2002, 2003-2004) have been re-computed by use of this improved procedure. Only slight differences should be noted when one compares the re-computations to previous releases of the Report. Details of this procedure are provided in Appendix A.