The mass per unit area of a circular disc (of negligible thickness) varies with distance
from centre ‘r’ as $\mathrm{\rho }={\mathrm{\rho }}_0\left(1+\mathrm{r}\right)$ where ${\mathrm{\rho }}_0$ is a constant. Its moment of Inertia about an axis passing through center perpendicular to plane is $\frac{{\mathrm{\pi \rho R}}^4}{10}(\mathrm{Y}+4\mathrm{R}).$ Then $\mathrm{Y}=\mathrm{\_\_\_\_\_\_\_}$ (taken the radius of the disc as R)