I still have my map of Dartmoor it must be 10 years old now, it has the ranges and danger areas all marked and is still in good condition as this was my spare kept in a waterproof bag in my Bergan.
Mine are the military maps and I have 1:50k and 1:25k so got a good amount of detail which helps a lot especailly with the ground and danger areas
Most of the maps I own are military, of where I have been and most of them are 1:50 they are 10 years old or older.
I'll check the date on my maps and i know they are the latest so I will let you know on the date on them is