Battery health deterioration

I've a MBA Mid-2011 model. As you see from Coconut Battery report; the age of the Mac is just 18 months and with 359 recharge cycles so far. The battery health has deteriorated so fast; now it hardly holds half-an-hour of power capacity.

From all the help and advice, I gathered from the web; I've tried SMC, PRAM reset and also recalibration of the battery. Also, upgraded to the latest version of the Mac OS X (10.8.2) in the hopes of finding some solution to this, but with no avail.

I understand that it should work for at least 1000 cycles or more. Could it be a faulty battery? Are there any other options apart from getting the battery replaced?