The depth below the surface of sea to which a rubber ball be taken so as to decrease its volume by $0.02 \%$ is _______ $m$.

(Take density of sea water $=10^3 \mathrm{kgm}^{-3}$, Bulk modulus of rubber $=9 \times 10^8 \mathrm{~Nm}^{-2}$, and $g=10 \mathrm{~ms}^{-2}$)