Get Layer's X and Y in comparison of Composition.

I need to get the X and Y coordinated of a layer in %.
For example I have a composition size 1280*720, and the layer of any size for example for now 150*75.
if the layer starts from very beginning of composition from top left then the X and Y will be 0% 0%;

If the layer starts from 640 and 360 then the layer coordinated should be 50% 50%;

Please help me out. Thanks in advance