the bogus chart suggests non-gun homicides occur about 44% more frequently than do homicides committed with guns. The FBI stats indicate about two thirds of homicides are committed with guns, about one third without guns, almost the opposite of the chart.
If you publicly argue with the bogus numbers, the media and other antis will use the FBI numbers to make you look like you haven't a clue and that you have an egregiously biased, unrealistic view; they will leave the general public with the idea that gun control advocates have won the argument, without the meat of the matter ever really being addressed.
I've been active for 40 years and I've seen this trick pulled before. The contradiction may seem like small potatoes, but when your opponents point it out, they will do it in a way that will, as the attorneys like to say, go straight to your credibility, i.e. everything else you say will be taken with a grain of salt.
Again, please don't use that chart, it is not accurate and it will only cost you credibility with the people you might try to convince by citing it.