$\mathrm{I_{CM}}$ is the moment of inertia of a circular disc about an axis (CM) passing through its center and perpendicular to the plane of disc. $\mathrm{I_{AB}}$ is it's moment of inertia about an axis AB perpendicular to plane and parallel to axis CM at a distance $\frac{2}{3}$R from center. Where R is the radius of the disc. The ratio of $\mathrm{I_{AB}}$ and $\mathrm{I_{CM}}$ is $x:9$. The value of $x$ is _____________.