Using OLS, we regress $y$ onto $X_1$ and find that the model has an $R^2$ of 0.45. We also regress $y$ onto $X_2$ and find that the model has an $R^2$ of 0.3. Let $[\min, \max]$ denote the lower and upper bound of $R^2$ of a model which regresses $y$ onto $X_1, X_2$. Find both the $\min$ and $\max$ $R^2$ values for the new model.