Article 4
1. In order to calculate the weighting of the various rates as referred to in Article 3, the Member State shall break down, by VAT rate applied, all transactions which are taxable under its national legislation and which do not entitle the customer to deduction of VAT, account being taken of Article 17 of Directive 77/388/EEC, and consumption on the farm by flat-rate farmers and their direct sales to final consumers. The VAT rates used for the purposes of such calculation shall be those which, in accordance with paragraph 7, affect the VAT revenue collected during the year in question. Transactions which are subject, pursuant to Article 28 (2) of Directive 77/388/EEC, to exemption with refund of the tax paid at the preceding stage shall be regarded as taxable transactions subject to a zero rate. 2. The breakdown by rate of VAT shall be applied to the following categories, if subject to non-deductible VAT: - final consumption of private households, including consumption on the farm by flat-rate farmers and their direct sales to final consumers, - intermediate consumption of private non-profit institutions and general government, - intermediate consumption of other sectors, - gross fixed capital formation of private non-profit institutions and general government, - gross fixed capital formation of other sectors, - improved and unimproved building land, as defined in Article 4 (3) (b) of Directive 77/388/EEC, - transactions involving gold other than gold for industrial use carried out in the territory referred to in Article 3 of Directive 77/388/EEC in respect of the Member State concerned. 3. For the purposes of the breakdown of final consumption, consumption on the farm by flat-rate farmers and their direct sales to final consumers shall be subject to a rate equivalent to the charge on inputs. 4. The breakdown of transactions by statistical category shall be effected by means of data taken from national accounts prepared in accordance with the European System of Integrated Economic Accounts (ESA). In order to calculate the VAT own resources base for any given financial year, reference shall be made to the national accounts relating to the last year but one before that financial year. A Member State may be authorized, in accordance with the procedure provided for in Article 13, to use data relating to another year, which may not be earlier than the fifth year before the financial year in question. 5. For the purpose of identifying transactions subject to non-deductible VAT and effecting the breakdwon by rate of VAT, Member States may refer to data taken from sources complementary to the ESA and capable of being adapted thereto, that is, is the first instance, from internal national accounts if they provide the necessary breakdown, or, if not, from any other appropriate source. 6. In order to determine the weighting of each rate, Member States shall calculate the relationship between the value of the transactions to which that rate applies and the aggregate value of all transactions. 7. Should a Member State amend the VAT rate applicable to all or some transactions or the tax treatment for certain transactions in such a way as to affect the VAT revenue collected, it shall calculate a new weighted average rate. The new weighted average rate shall be applied to the revenue derived from application of the amended rate or tax treatment. By way of derogation from the first subparagraph, the Member State may calculate a single weighted average rate. To this end, transactions in respect of which the rate or treatment has been changed shall be allocated to the old and new rates or to the old and new treatment pro rata temporis, with account being taken of the average period of time elapsing between entry into force of the new rate or treatment and the collection of revenue resulting therefrom, calculated over the entire year in question. This average period may be rounded off to the full month.