In May 2005, fuel in Belgium averaged €1.156 for petrol

Petrol, monthly average€1.156/L
Diesel, monthly average€0.951/L
LPG, monthly average€0.401/L
Weekly bulletins held for May 20055

Monthly averages for Belgium across May 2005, from the stored EU Weekly Oil Bulletin monthly history (European Commission, CC BY 4.0).