Global economic cost of terrorism is now at its highest since 9/11

In the wake of Friday's massacre in Paris, a new report says the world is paying the highest price for terrorism since the 2001 attack on New York's Twin Towers.

In 2014, acts of terror cost the world $52.9 billion - roughly the size of Bulgaria's entire annual gross domestic product - compared with $51.51 billion in the aftermath of Sept. 11, according to the latest annual Global Terrorism Index by the Institute for Economics and Peace, which has been collecting data since 1997.

To put a price on terrorism, IEP calculates the value of property damage, say from a suicide bombing in a building, and the cost of death and injury, including medical care costs and lost earnings. It doesn't take into account the increased number of security guards, higher insurance premiums, or city gridlock in the aftermath of an assault.

While the findings do not include the impact of Friday's carnage in the French capital - those will be quantified in next year's study - the economic consequences of Europe's worst terror attack in a decade so soon after January's Charlie Hebdo shootings will reverberate across the European Union almost immediately.

Islamic State has now overtaken the Taliban in Afghanistan to be the deadliest terrorist group, killing more than 20,000 people last year, the study showed.

French President Francois Hollande called IS "the biggest terrorist factory the world has ever known."