Table 3. Results of the final multiple regression model.

Variable	Coefficient	P-value	Overall P-value	95% Confidence interval	R2
GDP per capita (1000 EUR)	27.55	0.002	-	11.32; 43.79	0.82
Research excellence	97,560	<0.001	-	57,385; 137,736
Population (2nd quartile)	700,203	0.026	0.067	90,777; 1,309,630
Population (3rd quartile)	721,330	0.024		105,599; 1,337,061
Population (4th quartile)	293,956	0.328		-315,950; 903,861

GDP: gross domestic product