article: The deaths of 16 people in Barcelona and Cambrils earlier this month highlighted the continued threat posed by Islamist militants. The summer months have also seen new attacks in Belgium, France, Austria, Germany and the UK, as well as the first in Finland and one in the US. Although the vast majority of Islamist attacks are elsewhere in the world, an unprecedented number have taken place in Europe and North America since the declaration of a "caliphate" by the so-called Islamic State, in June 2014. The first look at the data behind the attacks - everything from the age of the perpetrators, to immigration status - offers an insight into those responsible and how they might be tackled. We identified 63 attacks between September 2014 and late August 2017 that we considered to be acts of jihadist terrorism. A relatively limited number of countries were affected: nine in Europe - those named above, plus Denmark and Sweden - along with the US and Canada. Regardless of country, most attacks were in large towns and cities - including Barcelona, London, Manchester, Paris, Nice, Berlin, Brussels, Stockholm and Orlando. A few attacks hit iconic targets, such as the Champs-Elysees and the Louvre museum in Paris, Westminster in London and Las Ramblas in Barcelona. Many others targeted crowded spaces such as busy pedestrian areas, entertainment venues or transport hubs. But some terrorist attacks have hit more unusual places, including an office Christmas party and a service at a church. We looked at attacks motivated by jihadist ideology, that involved deliberate acts of violence against other people and were intended to intimidate or convey a message to a larger group. Other organisations use different definitions. In total, the 63 attacks caused 424 deaths and left almost 1,800 people injured. The perpetrators are not included in these figures. The Paris attack of November 2015 was the deadliest, with 130 people killed, including 90 at the Bataclan theatre. France also saw the Nice lorry attack, which left 86 people dead. There were many other attacks that left many people dead and others injured. In total, these 11 attacks were responsible for 386 deaths. However, most of the attacks did not cause casualties, with the exclusion of the perpetrators. Although the number of young people being radicalised has caused concern, the average age of the attackers - 27.5 - is not unusually young. The two youngest were 15 - an unnamed boy who attacked a Jewish teacher with a machete in Marseille, and Safia S, a girl who stabbed a police officer at a Hannover train station. Of the five who were under the age of 18 at the time, four were in Germany. 15 Age of the youngest attacker 27.5 Average age of attackers 54 Age of the oldest attacker The vast majority of the attackers were in their 20s, with about one in four attackers above the age of 30 and six aged 40 or older. The oldest suspect, Mohamed H Khalid, was 54 when he was accused of stabbing to death an elderly couple in the
summary: A series of attacks in Europe over the summer months has raised the number of people killed in the West by jihadists during the past three years to more than 420, writes Dr Lorenzo Vidino.