Apple states that as long as your current full charge capacity is at least 80% of the design full charge capacity the battery meets their specifications. They will not do anything until it falls below 80%.
The percentage is calculated by taking the current full charge capacity from the Power screen in "System Information" and dividing it by the design full charge capacity which is 6700 mah for your MBA and then multiplying by 100.
It is extremely unlikely that your battery was ever at the design full charge capacity because it is currently impossible to manufacture a battery that will exactly meet the design target value.
Have you been running your battery down to zero charge bebore recharging it? If so stop doing that. It is the quickest way I know to kill a Lithium battery. Lithium batteries do not have "memory" problems and can be recharged at any charge level below 95%.
A battery is made up of several cells connected in series. When discharged to empty the weakest cell will die first and from that point on it will be charged in the reverse direction. Charging a cell in the reverse direction will quickly destroy it. Hopefully the battery control circuity in the MBA does not allow this to happen but I don't know if that is the case.
The 1000 charge cycle number is also a target. There is no way to design a battery that will last for exactly 1000 cycles.
