Mine are all still in storeage after house move, but form memory I can only think of 1, from about 7 or 8 years ago, which came apart, and this was due to my mishandling when looking up something (I bent the spine back and broke the glue)
My 2006/2007 ones have fallen apart, though I think its more than likely due to me being abit heavy handed with them lol. All the others are in mint condition (well except for tea stains on one... *rolls eyes*)
My catalogues from 2005 are in bits and pieces...the pages started falling out of the one from 2006...but all the other years are still intact (so far!)