Listen to what the pond tells you and react accordingly.
This is the absolute best way to self manage a pond. Low relative weights indicate excess competition (or low forage), so harvest is in order. There are several websites and articles out there that give the equation for relative weight. The easier method would be to download the Pond King App available in apple app store. The app has a section where you simply enter the length and weight to get an instant relative weight reading. Of course the ideal relative weight is 100%, but catch several fish out of the pond to determine your average before harvesting. If the weights are low then harvest bass that are on the bottom side of your average relative weight.
Furthermore, angling mortality should not be calculated into the harvest rates, because as mentioned by Meadowlark, angling mortality is highly dependent on to many factors to be an absolute. Personally, if I was having an issue with fish swallowing the hook, or simply not doing well after being caught, I would limit angling by inexperienced people, smash the barbs on all moving baits (spinnerbaits, crankbaits and topwaters), and use a net to bring the fish out of the water rather than hoist them up on the line. Those are just several practices that aid in healthy return of fish.