Despite an improvement in tax collection and plans to impose a new tax on properties valued over CR100m (US$24,000), government revenue will remain low relative to GDP in the forecast period. The government will therefore continue to depend on foreign grants and loans to finance its deficit, which the Economist Intelligence Unit estimates to have reached 5.6% of GDP in 2010. So far the country's donors, known collectively as the Cambodia Development Co-operation Forum, have pledged to provide US$958m in assistance in 2011 and US$751m in 2012. The government had hoped that oil production from fields in the Gulf of Thailand would provide new revenue in the form of taxes and royalties, but oil is now not expected to begin flowing until at least 2012. Weak revenue growth, combined with rises in expenditure (especially on defence and wages), will ensure that the budget remains in the red. The government does not issue Treasury bills or other securities, and it would therefore meet any financing shortfall by drawing on its deposits at the NBC, which have fallen from a high of CR3trn (US$740m) in April 2009 to CR2.2trn in January 2011, representing a decline of 29%.