Well he did serve half as long as the others, and we did come pretty close to a few. I don't think it's a very good metric regardless though, because it depends

Well he did serve half as long as the others, and we did come pretty close to a few. I don't think it's a very good metric regardless though, because it depends hugely on external factors and world politics which the President doesn't have as much control over. As war-mongering as Bush may have been, 9/11 was an external force. If something similar would've happened during Trump's presidency on US ground, I have zero doubt he would've started another war.