The percentage of pupils eligible for free school meals is frequently used as a measure of deprivation. This map shows the proportion of pupils eligible for free school meals who had reached a "good level of development" when starting school in 2009.
What is surprising is the uniformity across England: at 32 per cent, the North East has the lowest figure, but at 38 per cent London is the highest.
But drill down to the level of district councils and the gap starts to widen, with a gap of 24 per cent between the best and worst councils in the South East.
It is also striking that not all of the lowest percentages are in urban areas: some rural councils have low proportions of pupils on free school meals judged to have reached a "good level of development" on starting school.
If political parties are serious about ideas such as a pupil premium that funds learning needs, figures such as those shown on this map will help determine the allocation.
For years, urban schools have received the bulk of extra funding; perhaps at last pupils in some rural schools might also benefit from additional resources.
John Howson is a director of Education Data Surveys, part of TSL Education.