By how many percents will the focal length of a flat-convex lens change when it is heated from $0$ to $100$ degrees Celsius if, at $0$ degrees, the focal length is $F_0$ and the refractive index is $n$?

The coefficient of linear expansion of the lens material $\alpha=25 \cdot 10^{-6}~\mathrm{K}^{-1}$. The lens is made of material of density $\rho$. It can be assumed that $ n - 1 \propto \rho$