A homogeneous ideal gaseous reaction ${\mathrm{AB}}_{2\left(\mathrm{g}\right)}\rightleftharpoons {\mathrm{A}}_{\left(\mathrm{g}\right)}+2 {\mathrm{B}}_{\left(\mathrm{g}\right)}$ is carried out in a $25 \mathrm{litre}$ flask at $27°\mathrm{C}$. The initial amount of ${\mathrm{AB}}_2$ was $1$ mole and the equilibrium pressure was $1.9 \mathrm{atm}$. The value of ${\mathrm{K}}_{\mathrm{p}}$ is $\mathrm{x}\times {10}^{-2}$. The value of $\mathrm{x}$ is                 (Integer answer) $\left[\mathrm{R}=0.08206 {\mathrm{dm}}^3 \mathrm{atm} {\mathrm{K}}^{-1} {\mathrm{mol}}^{-1}\right]$