Don't forget to break out the US by-ethnicity numbers so you get a comparison of, e.g., European Americans to other particularly euro populations. For instance, US murder rate is about double that of Canada, but Euro population is ~at par.
I didn't forget. By your numbers blacks account for half of the murders. So take the US's 3.9 and divide it by half = 1.95. Compare that to Spain (which is full of hispanics, just to elimate that as a confounding variable) at 0.7, which has a 2.8 times lower murder rate than the US non-black population.
