This CD-ROM contains data and documentation files for the NAEP Reading and Mathematics Long-Term Trend assessments at age 9 for the years 1971, 1975, 1980, 1984, 1988, 1990, 1992, 1994, 1996, 1999, 2004, 2008, 2012, 2020, and 2022 for use in the analysis of NAEP data by secondary researchers. A Data Companion is provided in electronic portable document format (PDF). This document contains information on the contents and use of the data files as well as the assessment design and its implications for analysis. NAEP datasets from 2002 onward require a Tool Kit with the updated NAEPEX. Your organization must apply for and be granted a restricted-use data license in order to obtain these data.