You are able to deselect any event that you don't want to see on the graph and the graph will resize to fit the data. Do you still think it is worth it to make a separate graph. Because the way I see It most of the time the user would just keep those deselected and when they are interested in that data they can select it. But I can totally see wanting them to just exist in a separate graph if that is what you think is best and would be easy to change.