I take issue with the statement
"That means Sweden now has over 50% more murders than the former gang warzone."
Murder rate is usually reported as murders per hundred thousand people. Sweden having a population of just over 10 million, El Salvadore having a population of 6.5 million, the correct comparison is .320 murders per hundred thousand in Sweden to .307 murders per hundred thousand in El Salvador. Indeed Sweden for the period reported had a higher murder rate, but not 50% higher.
The statement as made is correct, but it is pointless. Doubtless the US has had more murders in absolute number than either, but given that we have 335 million people, that would hardly be suprising. Reporting absolute numbers, rather than incidence per 100,000 (the standardly used number, others would work, too) for things like murder, cases of a disease, and the like is at best naive at worst deceptive.