As others have mentioned, I think it's more likely referring to the amount of roller coasters in a given area than the amount of coasters in the park.
Also, I got those two facts from an extract of a Rob Brydon book named Notes From A Small Island that we had to analyse in English; I'm unsure of when it was published, so the facts may now be out of date.
It did also say that Blackpool Pleasure Beach was Europe's 2nd most visited tourist attraction behind the Vatican with 6.5 million visitors per year, which I think might be outdated.