Debt for the nation's school districts rose 12% to $226 billion in the 2001-02 school year, according to Census Bureau data released Tuesday.

The increase came when communities — many still paying off huge debts from the school construction boom of the 1990s — encountered mounting budget woes as the U.S. economy worsened.

In turn, schools struggled to meet the sobering challenges of hiring more teachers, reducing class sizes, fixing older facilities and meeting stricter educational quality guidelines, some advocacy groups say.

The Census Bureau figures, although the latest available, are two years old, and therefore don't account for the bulk of costs associated with the No Child Left Behind Act, the sweeping education reforms pushed by President Bush and signed into law in 2002.

"You've got enormous costs on the horizon for most school districts," said Daniel Kaufman, spokesman for the National Education Association.

The census figures, which cover public elementary and secondary school systems, show spending rose collectively about 6% to $435 billion.

Districts spent just over $7,700 per pupil, not accounting for costs related to construction or capital needs. That's up from $7,284 the previous year.

School enrollment in 2002 was just under 47.2 million, down slightly from the 2001 number, although it was impossible to tell if that was a true decline in enrollment because of a change in the way the Census Bureau compiled the data.