What is the oxidation state of oxygen of ${\mathrm{H}}_2{\mathrm{O}}_2$ in the final product when it reacts with ${\mathrm{ClO}}_3^{-}?$

The following equation is obtained as the reaction, 

${\mathrm{H}}_2{\mathrm{O}}_2+2{\mathrm{ClO}}_2\to 2{\mathrm{ClO}}_2^{-}+{\mathrm{O}}_2+2{\mathrm{H}}^{+}$

Since ${\mathrm{O}}_2$ is an element it has zero oxidation state.