Causation can be neither proven nor disproven with so few data points, especially since there's a lot of other correlations going on. For example, the high tuition WTA countries are also mostly former parts of the British Empire, with Britain having a somewhat different history of higher education and democracy than continental Europe, who takes up all of the spots on the Free Tuition side. So the cause might just be inheriting s particular system from Britain.
But PR and free tuition is of course superior.
Causation can sometimes not be proven with all the data points (full population). Sometimes statistics are not enough to prove causation.
Anyways, I like your analysis!
