Electrical rewire

[jimny1]

I was discussing this with my wife and was wondering how long it is recommended before a spanish property would require a rewire
I googled this and was surprised to see different times in different countries
For example , in spain an article is saying around 30 years , the uk around 25 years but the most surprising was the USA where it suggested 40 to 60 years , in fact another article said 80 years
Not being an electrician, but having some understanding about electrics having taken a course many years ago in college , i thought i might know the answer to why the wiring in the USA lasts so long, but i dont
The only difference between there and other countries is the current travelling through the wiring, but i dont think this matters
Maybe they use a different gauge of plastic for the outside covering as this is what deteriorates ?
I know weather could be a factor, but the USA weather is so diverse it doesnt answer the question
If anyone knows the answer i would be grateful ? cheers