What does this map of European Countries represent?

What does this map of European Countries represent?

It's Monday, time for another map question...

This map shows countries of Europe with a percentage shown for each.

What do you think this percentage represents?

Answer will be given in a few days... Wednesday.

Updates
2 mo
This map shows home ownership. Within each country, how much of the population owns their own homes versus renting or leasing.

Congratulations to those who got this right.
What does this map of European Countries represent?
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