With that much reflected power from an antenna with an SWR of 5.1, your radios TX final might not last long either.
This chart does bring up a good point. A lot of guys think you need that low SWR reading of 1.1. I'm happy with a reading around 1.4 to 1.5.
So if my CB radio is putting out the legal 4 watts, then at 3% loss (per chart), my reflected power loss is 120 milliwatts. If my radio is putting out 100 watts, then with a 3 watt loss, no one is going to notice.