Another example in the EU, historical buildings (that were built before 1945) constitute 26% of existing building stock \cite{2015}. In Italy, historical buildings include buildings that were built till before 50 years according to legislative decree no. 42/2004. So, there are 6599 historical buildings in Italy because they were built before 1945. These historical buildings constitute 24.20% of the built environment \cite{troi2011historic}, Ref. to figure no. (3) and (4) to compare between total number of historical buildings in the EU, Italy, and Cairo.