prOOne
Just to agree/reinforce Jess the Dog's point. Most of the people I meet in Iraq are on 2, 3, 4 and at most 6 month deployments. Even the Black Watch only did 6 months. Therefore while we might only have 4.6% depoloyed at any one time (which I doubt includes NI as that will no doubt be considered part of the UK), YOU HAVE TO MULTIPLY THAT BY A FACTOR TO FIND THE NUMBER/PERCENTAGE DEPLOYED IN ANY 12 MONTH PERIOD.
As already stated certain units/specializations deploy more frequently than others, for example I would assume artillery and Tank units are deploying less frequently than infantry units. In the same way the UK AEW fleet isn't spending time in sandy places, but it has become a way of life for the SH boys.
As I have already stated, overstretch is not even across the armed forces, but that does not mean it does not exisit.
Statistics need to be relevant to be of any use. I would suggest looking at % deployed at any one stage is an oversimplification.