SATS are bollocks and yet we all get taken in by them, even when we start off by saying it's the school that counts
IMHO the scores mean virtually nothing, nothing to crow about. Each year a different cohort of children will be taking the SATS so you're judging your school on individual children's abilities
whilst doing so, please bear in mind:
that children who move into the school are included, ie those who can hardly be deemed to have benefited from the schooling provided by that school over the last 4 years
that no allowance is made for those speaking english as a 2nd language AFAIK
that this is just reading, writing, maths and science. No other subject counts.
that children with severe SEN will be included in the averaging out .. hence a child who could never be expected to equal national average due to his / her mental capabilities will bring the school's scores down