Saudi Arabia has netted a whopping sum of nearly $2.5 trillion from oil exports over the past 42 years and more than half of the income has been earned in the past 11 years, according to official data.

During 1969-1970, the Gulf kingdom pumped over 70 billion barrels of crude from its massive desert fields, fetching it a total SR9.36 trillion ($2.5trn), showed the figures by the Saudi Arabian Monetary Agency (Sama).

More than half the income was netted during 2000-2011, when it totalled at nearly $1.49 trillion. The Kingdom, which controls over a fifth of the world’s extractable crude deposits, basked in its highest oil export revenues of nearly SR1.1trn ($294bn) in 2011, when oil prices climbed to their highest average of nearly $100 and the country pumped at one of its highest oil production levels of around 9.2 million bpd.

A breakdown showed Saudi Arabia, the largest Arab economy, netted its second highest oil income of SR983bn in 2008 as oil prices were at one of their highest levels of nearly $95 a barrel.

The report showed sharp fluctuations in Saudi Arabia’s revenues over the past four decades because of persistent volatility in oil prices and production by the country, which has long acted as a swing producer given its massive reserves and large idle spare capacity.

In 1998, when oil prices averaged just around $12 and Riyadh produced little above five million bpd, its income dipped to only SR79.9bn, less than 10 per cent of the 2011 earnings, the report showed.

Saudi Arabia earned only about SR5.1bn in 1969 and the income began its steady climb over the following years because of higher prices and output. It maintained its rapid climb to shoot above SRT100bn in 1976 and leap to nearly SR320bn just 10 years later. After 1980, the country’s oil revenue started to suffer from persistent instability because of changes in prices and production triggered by political and market factors.

The sharp fluctuations in the income were reflected in Saudi Arabia’s fiscal balance, which has kept swinging between a surplus and a deficit.

Riyadh reported its largest ever fiscal surplus of SR580bn in 2008 while it suffered from its worst deficit of SR170bn during the 1990-1991 fiscal year, which combined the budget of both years due to the Gulf war.

The surge in the country’s earnings over the past 10 years allowed it to replenish its eroding foreign assets, which more than tripled to nearly SR2,000bn at end-November.