PLA printings always ~0.22% larger
You are not taking into account die swell.

When printing with a 3D printer hot plastic is forced through a nozzle, which leads to the expansion of the material. The result is, that with 0.4 mm nozzle and 0.4 mm intended line width, the material will actually deposit some fraction of a millimeter wider. In your test case, that is 0.22%. If you'd print a double-sized test piece, I expect 0.11%, and in case of a half-sized 0.44% - in other words, it is a static offset.

Because of this, it is usually better to demand wider lines than the nozzle is, forcing the die swell effect to become negligible in the wider line. I managed this with about 110% of the nozzle width on my machines.

Further Reading: Why is it conventional to set line width &gt; nozzle diameter?