I am the currency of a nation known for its fjords, Vikings, and the Nobel Peace Prize. My value is tied to the strength of oil and natural gas production. I am not part of the Eurozone.

1. My name starts with 'N'.
2. My symbol is 'kr'.
3. I am used in a country that is not part of the European Union.
4. The central bank that controls my value is located in Oslo.