Measured in barrels of oil equivalent (boe), our proved reserves consist of 31% oil and 69% natural gas, based on total proved reserves on the NCS of 4529 mmboe.

The following table shows our proved reserves of NCS crude oil and natural gas at the end of the periods indicated. The data is net of royalties in kind, but includes reserves attributable to our account based on our proportionate participation in fields with multiple participants. No major discoveries or other favourable or adverse events have occurred since 31 December 2008 that would mean a significant change in the estimated proved reserves as of that date.

Further information on reserves can be found in Note 34 - Supplementary oil and gas information - to our Consolidated Financial Statements.

		Oil/NGL	Natural gas		Total
Year		mmbbls	bcm	bcf	mmboe
2008	Proved reserves end of year	1,396	498	17,581	4,529
	of which, proved developed reserves	1,113	410	14,482	3,693
2007	Proved reserves end of year	1,604	535	18,893	4,971
	of which, proved developed reserves	1,187	427	15,084	3,875
2006	Proved reserves end of year	1,667	541	19,129	5,068
	of which, proved developed reserves	1,188	379	13,378	3,566