 Recent evidence by Kemp and Stephen (1999) has tried to estimate hypothetical Scottish shares of North Sea Oil revenue by dividing the UK sector of the North Sea into separate Scottish and English sectors using the international principle of equidistance as utilised under the United Nations Convention on the Law of the Sea (UNCLOS) - such a convention is used in defining the maritime assets of newly formed states and resolving international maritime disputes.The study by Kemp & Stephen showed that hypothesised Scottish shares of North Sea oil revenue over the period 1970 to 1999 varied, dependent upon the price of oil and offset against taxable profits and the costs of exploration and development.Nevertheless, a Scottish share of North Sea oil is never formally alluded to as part of Scotland's net fiscal position and is treated by HM Treasury as "extra-regio" resources.