Which tire has the highest Treadwear (UTQG) in size 185/50R16

It's time to buy new tires for my car, but I want to buy a tire that lasts longer than the original brand, OEM. Which tire has the highest Treadwear in this size 185/50R16?

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500 - Treadwear

 Continental ProContact TX - UTQG: 500AA - Tire Rating: 0

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320 - Treadwear

 Marshal Matrac XM KH35 - UTQG: 320AA - Tire Rating: 4.38

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280 - Treadwear

 Toyo Proxes T1R - UTQG: 280AAA - Tire Rating: 4.65

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