In order to estimate  ${\text{O}}_{\text{3}}$ in the air , 22.4L of air at 1atm and ${\text{0}}^{\text{o}}\text{C,}$ is passed through acidified $\text{KI}$  solution where  ${\text{O}}_{\text{2}}$ is evolved and ${\text{I}}^{\text{-}}$  is oxidized to ${\text{I}}_2.$ The liberated  ${\text{I}}_2$  required 200mL of 0.1M ${\text{Na}}_{\text{2}}{\text{S}}_{\text{2}}{\text{O}}_{\text{3}}$  in acidic medium, then what will be the % composition of  ${\text{O}}_{\text{3}}$  by volume in the sample?