What amount of odometry drift would be considered having an accurate base?

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I'm working on some projects and it occurred to me that I've never seen any documents where people specify their robot base odometry drift to benchmark what a typical amount of drift would be and what's the point where I can say I have "good" odometry.

For instance, when I move my base in a 20 meter perimeter square, in forward direction I have about 20cm drift (1%) and in the lateral direction, I have about 50cm (2.5%) drift on a differential drive base.

Can anyone share here their specification or documentation of others?