Yet, little national data on student achievement in those schools is available.

The diversity of the city's poor people was also mirrored in the national data.

Still, by working through national and international data, it's possible to piece together what's happening.

The national data are not representative of what is going on in every region.

The number dropped to about 390, or 9 percent, in 2001, the most recent year for which national data is available.

There are almost no national data to put the problem into context.

After three years all national data were to be made available to the Commission for a new overview.

But starting today, the service will begin to report national data, both on television viewing and product use.

These national data are not very useful to local districts.

The ministry is to issue new national data on Tuesday.