1-7 were all Uematsu, 8-9 were all Uematsu except Hamaguchi helped arrange the streaming tracks (of which there were a lot more in 9; he did the ones in 10 and 11 too), 10 was co-composed with Masashi Hamauzu (SaGa Frontier 2) and Junya Nakano (Threads of Fate) (they split it up roughly equally, about 20-30 tracks each), 11 was mostly by Naoshi Mizuta (Parasite Eve 2; the expansions were entirely by him) with a minority of tracks by Kumi Tanioka (Crystal Chronicles) and just ten (good) tracks by Uematsu, 12 was mostly Hitoshi Sakimoto (Vagrant Story) with some help from Masaharu Iwata (Baroque) and Hayato Matsuo (Front Mission 3), and Uematsu only contributing the (wildly incongruous) vocal ending theme, arranged by Kenichiro Fukui (Einhander). 13 will be mostly (entirely?) by Hamauzu except for another vocal theme by Uematsu (let's hope it's not as jarring this time).
By the way, Blue Dragon and Lost Odyssey are arranged with Satoshi Henmi (does most of the rock/pop stuff, and plays the guitar parts) and Hiroyuki Nakamura (does most of the orchestral stuff), who probably deserve as much credit as Uematsu. They make a good team, though Nakamura is still pretty uneven.