'Proportion' in the Bible

If there are still many years [before the Year of Jubilee], in proportion to them he must refund [to the purchaser] part of the price of his sale for his redemption and release.

But if he consecrates his field after the Jubilee, then the priest shall calculate the price for him in proportion to the years that remain until the Year of Jubilee; and it shall be deducted from your valuation.