And here's what I made with it.
Why since 2006? Well, in 2004 new ward boundaries were drawn and all three councillors per ward were elected at once in a special election--which oddly enough was the first election I voted in after turning 18. And then there was no vote in 2005 so 2006 was the first 'regular' one.
South Yorkshire looks uncannily like Hungary.
Very nice work.