Mr. Philip Hughes:

Off the top of my head, I do not know the exact percentage, but I know from talking to my military colleagues in Brussels that France and Germany have quite large chunks of airspace set aside for exercises. Interestingly, they are considering how they can integrate with different member states to have joint solutions. This was really brought on by the introduction of F-35s. They need a bigger playground, not so much because of their speed but because they can see farther ahead. The military are looking at ways of sharing airspace to minimise the amount required. They are also considering the flexible use of airspace so that when finished doing the exercises, they can hand it back to the civil authorities.