Until the turn of the 21st century, high school graduation rates in New York City hovered at or below 50 percent, much lower than state and national averages. There was widespread agreement about the need to reform the City's high schools and produce better results for students. These technical appendices presented in chart form, provide statistical data to accompany the "The Condition of New York City High Schools: Examining Trends and Looking toward the Future. Data Brief." The data brief describes dramatic shifts in the supply of high schools, most notably a trend toward smaller, more mission-driven schools of choice. It also reports steady improvement across many indicators of high school performance and engagement, including attendance, credit accumulation, graduation, and college readiness rates. A glossary is included at the end of the appendices. [For the data brief, "The Condition of New York City High Schools: Examining Trends and Looking toward the Future," see ED561002.