To some, the differences between exam targets across England may seem shocking.
The figures, printed together here for the first time, suggest pupils from the same ethnic group can be expected to do 10 times worse in one area than in another in this summer's exams. How high a teacher's aspirations should be for a pupil appears to be a matter of their postcode and skin colour.
But, as most teachers know, statistics can paint a very misleading picture of schools. For example, on the face of it Trafford council has high hopes for its Bangladeshi pupils: 100 per cent are predicted to achieve five good GCSEs, including English and maths, this year.
But that may look different in light of the fact that only two Bangladeshi pupils in Trafford schools are due to sit their GCSEs this year, and both achieved the expected levels in maths, English and science in national tests as 14-year-olds.
In Suffolk the raw predictions look low for a number of ethnic groups - just 20 per cent of Indian-heritage pupils are expected to reach the threshold. But this is based on just 15 pupils. Next year, the target rockets to 77 per cent.
The targets, which the Government began to collect in 2004, were not supposed to be quite so small in scale: the advice to authorities is that they are not needed when there are fewer than 30 relevant pupils. Some argue that the targets should not be collected at all.
The scale of the targets is certainly bewildering, with separate goals for up to 21 ethnic groups, being collected from 150 authorities, with two measures for key stage 2 exams in primary, four for 14-year-olds and three for GCSEs.
Stephen Gorard, professor of education research at Birmingham University, said: "I am in favour of the basic idea underlying the initiative, saying: 'Look, we have these disparities - do we just accept them, or do we see if we can do something?' But setting these targets is a national policy which, in terms of the time and money spent on it, is considerable. That huge amount of time and money could be spent on extra classes, extra teachers for those targeted groups."
The foundation for all these targets is teachers' opinions. The local authority targets are aggregated from targets submitted by schools, which are in turn based on teachers' knowledge of their own pupils.
The aim of setting targets by ethnic minority, according to government guidance, is to identify and address the underachievement of particular groups of children. But looking at the figures on a national scale, it becomes clear how much of a role class has to play.
Dr Steve Strand, reader in education at Warwick University, has conducted research into how race, gender and class interact. "Looking at black Caribbean children in different authorities misses the effect of social class, which may be different in Gloucester than in Hackney," he said. "You wouldn't necessarily expect them to be the same because they might have very different home circumstances."
But research has discovered that ethnic minority achievement is not simply a reflection of a group's social status - Pakistani children do better than white children in the same social class, while black Caribbean children do worse.
Dr Strand said: "I'm in support of target-setting when it is properly managed. It can have a shock value. It makes you realise locally how big disparities can be. More useful is looking behind that to see why. But if it is going to be effective, it has to be at the level of individual pupils and it has to be linked to action."
In Suffolk, which has the lowest stated targets of the authorities for black Caribbean, Indian, black African and mixed race pupils, the data is being used as an impetus to fund staff training, employ teaching assistants and identify further challenges. Work on improving maths scores for black pupils will begin next year.
Derek Merrill, head of minority ethnic and Traveller achievement at Suffolk County Council, said: "It is useful for highlighting where there may be particular issues."
The targets are expected to show an upward trajectory, but the Government has accepted that population changes may mean that is not always possible. It has pledged to challenge authorities which set targets at lower or the same level for particular ethnic groups, as well as those which set the same target for all pupils, because it suggests they are not looking closely enough at individual pupils and groups.
Newcastle and Barking and Dagenham have both done the latter for 2008, setting targets at 41 per cent and 43 per cent respectively for all pupils. From next year, the targets will be changed to show progress as well as attainment.
Some may question the value of setting targets at all when underachievement of some ethnic groups is so long-standing. But David Gillborn, of London's Institute of Education, said they were crucial to stop the gap between groups widening. "If you look at the history of race and education in Britain, going back to when policy-makers started talking about it post-war, you see that if you don't require schools and local authorities to set targets to close the gap, those inequalities do not just persist - in many ways they get worse," he said.
"People think high expectations are a wishy-washy thing, But they are given institutional force through systems like setting by ability and GCSE tiering. Those barriers are literally impenetrable.
"This is important data because it raises serious questions about whether our education system will deliver on the rhetoric."
HIGHEST AND LOWEST
The authorities at opposite ends of the target spectrum
Hammersmith and Fulham 68%
Telford and Wrekin 9%
West Berkshire 100%
Mixed race total
Barking and Dagenham 43%
East Sussex 10%
What does this mean?
This table shows targets for the proportion of pupils predicted to get five A*-C grades this summer at GCSE, including English and maths, in eight ethnic groups. A fuller version of the table is available on the TES website, which has listings for white Irish pupils; white Travellers; mixed white and black Caribbean; mixed white and black African; mixed white and Asian. These are omitted here as fewer authorities provided data. Gypsy pupils were the only ethnic group for which no authority thought more than half would reach the standard. Figures for "white other", including east European immigrant pupils, show the national average target was 49 per cent, slightly below the white British target of 51 per cent.
Full table on www.tes.co.uk. Primary targets in next week's TES.