So, it turns out that this last volume alone represents over a third of the Harry Potter reading you will do to date! If the next volume grows at the following historical rates then this should provide you with valuable guidance as to the strength of rucksack that you will require in order to transport it to the park. It is with this in mind that I am assured by the publishers that J K Rowling has already tentatively named book six - 'Harry Potter and the Impossibly Bad Back Strain'.

Amidst all this serious mathematics I decided to pop over to Amazon.com and compare Mr Potter to that other famous magician of the written word, Leo Tolstoy. It turns out that 'War and Peace' comes in at a mere 1408 pages. So, if J K Rowling is able to produce the same quantum leap in the number of pages that she wrote between books 3 and 4, then she will successfully have overtaken this famous Russian author as the door-stop/desk-leveller of choice. If she then carry's out the same trick for the final book, and achieves the optimum growth pattern (100.63%) then we are all set for a book of truly gargantuan proportions which will require a set of elephants to get it home from the bookshop.