"Merseyside" is a VERY big area
as shown here, it's everywhere surrounded by red. , doesn't necessarily mean the wirral, it includes Liverpool, Southport, St. Helens, and nearly to Wigan and Warrington...
Liverpool i feel accounts for the bulk of these statistics as i'm fully aware the gangs over there use pitbulls and staffs as weapons rather than pets. and because they're wrongly trained attack dogs, they'll attack bloody anything.
don't get me wrong, i'm not proud merseyside is the #1 for this, i'm just trying to say that the Wirral is probably not accountable for much at all... except maybe birkenhead...