All those different awards ('prestigious' or not) make up for an interesting topic of business-social study... :-)
Awards are handed over through several interconnecting industry hubs. IAAPA itself, Liseberg, TEA, etc..
"Pomme d'Or" (FIJET, the European association of professional travel writers and journalists) could be regarded the only more or less leisure capital independent award amongst the others, who are all constructed "by and for the industry members" themselves. From those industry associations, it's a marketing tool for the industry as a whole, not a truthfull (independent) benchmarking. There is similarity between the classic merry-go-round and these awards. The horses represent the big boys in the club. Every horse gets a honorary trophee, one after the other, every year again. The other horses applaude as it's just a matter of time to get the next award. The merry-go-round just goes around, and around, and around....
I know the opera play from within, having been an IAAPA member for years. One would be amased how well orchestrated all this is !
It does not mean that the awarded parks are a bad choice. It's rather saying that MOST all are good choices, for quite some different aspects, and this in a steady way. Impossible to hook this up to a specific year. It's just an industry game and a constructed reason "to put the business-heads together" in a festive way, at least once a year.
I could write an appraisal text for literally almost every theme park in the world. It's not that difficult, it just needs a good dose of classic spinn doctor's autourship.
All by all, I like to say: please, place those awards in the righfull context of the leisure industry's big marketing machine, do not expect it to tell any specific timed truth. :-)
And remember: all those small attractions in the shadow of the big brothers, who are NOT powerfull enough to weigh in (by lobbying money) with them, wil never appear on the list of the awards. However, I do learn much more from the small guys then from the big brothers. To bring quality experiences on their extreme tight belt budgets is the real honorable kind of prestation !