No one answered you so far; quite long ago, but lets add something:
here are some helpful topics spread, search for trespassing or "razor wire"
one link:
http://www.theanswerb...l/Question907448.html
Build some passive security features which annoy the guys, like motion triggered floodlight (out of stone through reach) and fake cameras.
Reinforce your fence, so they need heavier tools, plant blackberries (no joke)
It's England, the crooks sue you if they get injured while stealing your stuff.
In (some) other countries they wouldnt dare to climb into a property without knowing the defences...they dont want to lose an arm or leg, or more.
some advice on this link, found it in here:
http://www.protecting...evention-methods.html