The boroughs that make up inner London are unique: pupils with English as a second language outnumber native English speakers among those who achieved five A*-C grade GCSEs in 2010 (including English and maths).
Although state education in London has received a bad press in recent decades, the combined outcomes of programmes such as the London Challenge and Teach First meant that non-native speakers did better in the capital than in any other region.
But among those whose first language is English, it was those educated at inner-London schools who produced the worst results in the country, with only 51 per cent achieving the five A*-Cs standard, including English and maths.
Outside London, the percentage of pupils whose first language is English and who achieved the five A*-Cs including English and maths in 2010 was in a narrow range of 53 per cent to 57 per cent. For pupils whose first language is not English, the range was from 42 per cent in Yorkshire and the Humber to 53 per cent in the South East.
Of course, within these aggregate percentages, especially for those whose first language is not English, lies a host of differences. These include how long a pupil has been in the country and when they started to learn English, and how we determine who falls into the second language English group, when many minorities are second or even third-generation UK born.
If our international rankings are going to improve we need to be able to cope with a multi-lingual pupil population. It is noticeable that many countries that score highly in international studies are mono-linguistic nations with relatively few speakers of other languages in their schools. We can start by ensuring that all schools have the same level of resourcing as schools in London.
John Howson is director of Education Data Surveys, part of TSL Education.