A 10kt (straight down the runway) headwind for pretty much MTOW ..... whatever "pretty much" might mean?
The average wind for Oxford during July is south westerly at 7.8kt!
Some S2000 performance data here:
Saab Aircraft Leasing
Oxford runway data here:
London Oxford (Kidlington) Airport EGTK/OXF - General Airport Information/Airfield Data for Pilots - Flight Planning