Yes, 551 has been decommissioned at the end of 2012 i have missed that, but i found a source on China Defense Blog they are usually very accurate on these things. I have updated the Wiki article on the Type 053 Jianghu its still not perfect i think that alot of the decommissioning dates are still wrong. But since there is no official confirmation on 517 and 518 i still put the numbers of Jianghu's at 15. 517 and 518 are probably already decommissioned and if not then they will be soon enough. This means that China has less than the 70 DDG's and FFG's that i always thought they would maintain and if true that 517 and 518 are already decommissioned that means that the PLAN now only has 67 DDG's and FFG's in her fleet. But it also means that the Type 054A has now replaced the Jianghu's as the most numerous ship in the PLAN fleet.