Dear Muhammad,

I am aware of an old study that relates to your question. It is "Economics of the Construction Industry, A Research Report from the Conference Board, Studies in Business Economics No. 111," by Peter Cassimatis. The calculation is derived from many tables which I attach.

Good luck in your research

Have you thy searched the internet thoroughly?

There is a good book used by Quantity Surveyors called MEANS, which has such information.

Check out the article accessed through this link;

https://www.academia.edu/34679429/Construction_Labour_Productivity_and_Its_Improvement