Boko Haram overtakes ISIS as world's deadliest terror group

But another militant Islamist organization overtook ISIS to become the world's deadliest terrorist group last year, according to a new report.

Boko Haram, the Islamic extremist group based mainly in Nigeria's northern states, was responsible for 6,644 deaths in 2014, an increase of 317% from the previous year, according to the Global Terrorism Index, released Tuesday.

By contrast, ISIS, the terror group to which Boko Haram reportedly pledged allegiance in March of this year, was responsible for 6,073 deaths.

Between them, the two groups were responsible for more than half (51%) the deaths attributed to terrorism, in the deadliest year on record for terror, according to the report.

Internationally, deaths from terrorism experienced a "dramatic rise" in 2014, increasing by 80% from the previous year, according to the study by the Institute for Economics and Peace.

There were 32,658 people killed in terrorist attacks last year -- nine times more victims than there were in 2000, it says.

School kidnappings, market bombings

Boko Haram, whose name means "Western education is forbidden" in the local Hausa dialect, gained international notoriety for its raids on schools, in which hundreds of girls have been kidnapped.

An estimated 276 teenage girls were snatched from a boarding school in Chibok in Nigeria's Borno state in April of last year, sparking the #bringbackourgirls campaign on social media.

The group -- whose elusive leader, Abubakar Shekau, has a $7 million U.S. government bounty on his head -- has also pursued a ruthless campaign of bombing marketplaces throughout Nigeria.

The country was rocked by two such blasts within 24 hours this week, with at least 31 people killed Tuesday in the northeastern city of Yola, according to a local Red Cross official, and 15 killed in Kano, about 400 miles (645 kilometers) to the northwest, according to police.

An 11-year-old girl was a bomber in one of the attacks.

Boko Haram's campaign of terror, combined with the rise of Fulani militants operating in the country's central belt, has led to Nigeria experiencing the biggest year-on-year increase of deaths from terrorism ever recorded, with 7,512 fatalities in 2014, up more than 300% since the previous year.

Fulani militants, hailing from a pastoralist ethnic group engaged in conflict with farming communities, were responsible for 1,229 deaths last year, making them the world's fourth deadliest terror group, according to the report.

Where is terror happening?

Iraq continues to be the country most impacted by terrorism, with 9,929 terrorist fatalities last year, the highest ever recorded in a single country, according to the report.

The number of countries experiencing more than 500 terrorism deaths increased from five to 11 in 2013. The six new countries on the list are Somalia, Ukraine, Yemen, the Central African Republic, South Sudan and Cameroon. The report adds that Ukraine entered the list because of the downing of Malaysia Airlines Flight 17 by a missile in a rebel-controlled area in the east of the country, killing all 289 people on board.

Most deaths from terrorism are not taking place in the West. Excluding the 9/11 attacks, since 2000, only 0.5% of deaths from terrorism have occurred on Western soil.

Of the attacks that did take place in the West, "lone wolf" attackers are the main perpetrators, causing 70% of all deaths since 2006.

How do we stop 'lone wolf' attacks?

The majority of "lone wolf" attackers are a mixture of political extremists, nationalists, racial, religious and white supremacists and, to a lesser degree, Islamic fundamentalists.

(CNN)