were 45 in 2018. Ethnicity is not recorded and published for either suspect or convicted criminals, but according to police intelligence chief Linda H Staaf many are second or third generation immigrants, are members of disadvantaged groups and have grown up in disadvantaged areas. Geographic distribution Most of the attacks were earlier recorded in low-income suburbs in Malmö, Gothenburg and Stockholm. In a more recent trend, more affluent districts also experienced attacks, such as a detonation in Bromma. Timeline of noted bombings According to a December 2018 Swedish Television interview with researcher , Sweden has a high number of hand grenade attacks compared to neighbouring countries Denmark, Norway and Germany. While gun homicides were on the rise in the 2011-2018 time span, according to a study at Malmö University the number of hand grenade attacks had shown a strong increase in the same period and a total of 116 hand grenade detonations were recorded. Rostami said criminologists in Sweden do not know why there was a strong increase and why Sweden has a much higher rate than countries close by. 2012 In 2012 the Swedish National Forensic Centre investigated 88 incidents involving explosives. 2014 1 December, Malmö: Malmö District Court was targeted by a bomb attack which was powerful enough to destroy the entrance of the building and also damaged windows and balconies of nearby buildings in a detonation which caused no personal injury. As a result, the decision to place the court building of a volatile city in a residential area was questioned. By October 2017, the crime had not been solved. 2015 12 June, Malmö: two men are lightly wounded after a detonation in the Seved area. 24 July, Malmö: a social welfare office in the south west of Malmö is damaged by a hand grenade. 5 August, Trelleborg: a social welfare office is damaged by a hand grenade. 2016 In 2016 police forensic experts reported that the number of annual investigations had increased from 100 to 150 annually in the 2014-2015 time span. According to Amir Rostami, 2016 saw a record number of hand grenade attacks. 2017 In 2017, the Swedish National Forensic Centre investigated 211 incidents involving explosives, of which 43 involved hand grenades. 1 January, Katrineholm, a grenade was thrown at the local police station. The entrance, several windows and three cars parked nearby were damaged. 18 October, Helsingborg: a hand grenade destroyed the entrance