Inane fact for the day

[kiwifruitbat]

According to Wikipedia...

Harry Potter and the Philosopher's Stone (UK) has 223 pages.
Harry Potter and the Sorcerer's Stone (US) has 309 pages.

Harry Potter and the Chamber of Secrets (UK) has 251 pages.
Harry Potter and the Chamber of Secrets (US) has 341 pages.

Harry Potter and the Prisoner of Azkaban (UK) has 317 pages.
Harry Potter and the Prisoner of Azkaban (US) has 435 pages.

Harry Potter and the Goblet of Fire (UK) has 636 pages.
Harry Potter and the Goblet of Fire (US) has 734 pages.

Harry Potter and the Order of the Phoenix (UK) has 766 pages.
Harry Potter and the Order of the Phoenix (US) has 896 pages.

Harry Potter and the Half Blood Prince (UK) has 607 pages.
Harry Potter and the Half Blood Prince (US) has 652 pages.

Harry Potter and the Deathly Hallows (UK) has 607 pages.
Harry Potter and the Deathly Hallows (US) has 759 pages.

Same books, different country.

Any guesses why the US version has a minimum of 50 pages more than the UK version, and is more often 80+ pages more than the UK version?

Illustrations might add a few pages... but that many? Come on folks - something is wrong here.