An equipment has been purchased at an initial cost of $₹ 160000$ and has an estimated salvage value of $₹ 10000$. The equipment has an estimated life of $5$ years. The difference between the book values (in ₹, $\textit{in integer}$) obtained at the end of $4^{\text{th}}$ year using straight line method and sum of years digit method of depreciation is______________