Changes in Data from Year to Year
The federal government required changes in how each state counts highly qualified teachers this year. In 2004-05, an elementary teacher was counted once for all classes taught. In 2005-06, each of the 5 or so classes taught by each elementary teacher counted separately.
To the extent that elementary teachers are often more highly qualified, that additional weighting this year could affect some overall district totals.
Therefore, the best comparison is within subjects (English, math, etc.) and within categories (elementary, middle/high school), where there was NO relative change in the federal rules for counting highly qualified teachers.