I didn't see Mexico on that list.
Number six overall and the murder rate is 4.5X the US rate. The data is badly skewed because there is no suicide rate and therefore there are likely thousands of more gun deaths annually. But that can all be explained by the thugs and criminal organizations selling guns in the US to criminal gangs.
Now how you explain the fact that the criminal organizations in the US that have them don't just use them to kill people in the US is a head scratcher.
It does not seem to make any sense that they would have to send the guns to Mexico and then kill people with them. It is a very inefficient process to say the least.