Oil rig (2)

Oil prices took another tumble on Thursday, falling below the $33 mark for the first time since 2008.

On Wednesday, prices dropped below $35 per barrel for the first time since July 2004. But Brent crude oil fell 4.7% to $32.62, marking the first sub-$33 price since April 2004.

US oil dropped 3.9% to $32.40, it's lowest price since December 2008.

Brent crude prices as now 70% lower than around 18 months ago, when the downward trend started at more than $110 per barrel.

Prices have been falling due to huge over-supply. Oil producing nations are supplying far more oil than the world currently needs. Many experts have called for Opec (Organization of the Petroleum Exporting Countries) to dramatically reduce production. But Saudi Arabia, which leads Opec, has remained adamant that it will not decrease the amount of oil being produced.

Additionally, the Chinese central bank has taken steps to reduce the value of the yuan against the US dollar in order to boost exports. Typically, demand for oil falls when the US dollar is stronger against oil consuming countries. China is one of the world's biggest consumers of energy and oil.