The US economy grew by an annualized rate of 5.7% between October and December, official figures have shown.

The number, which is a first estimate, is a big rise from the previous quarter’s growth rate of 2.2%.

It suggests the country’s economy is growing at its fastest pace for six years and confirms the US economy has left its year-long recession behind.

But even with the rebound, gross domestic product (GDP) shrank by 2.4% across 2009 as a whole.

That was the worst annual performance since 1946. US GDP is expressed as an annualized rate, or annual pace, which shows what the three months’ economic activity would mean if it carried on for a year.

The Bureau of Economic Analysis, which releases the data, emphasized that the fourth-quarter advance estimate was based on incomplete information and was subject to further revision.

Growth in the third quarter was originally estimated at an annualized rate of 3.5%, but was revised down to 2.2% after more information was received.