Borrowing at floating rates as described in note 27 exposes the group to cash flow interest rate risk, which the group manages within policy limits approved by the directors. Interest rate swaps and, to a limited extent, forward rate agreements are utilised to fix the interest rate on a proportion of borrowings on a reducing scale over forward periods up to a maximum of five years. At 31 December 2015 the nominal value of such contracts was £109m (in respect of US dollar) (2014: £103m) and £52m (in respect of Euro) (2014: £54m); their weighted average interest rate was 1.3% (US dollar) (2014: 1.3%) and 0.6% (Euro) (2014: 0.6 %), and their weighted average period to maturity was two years. All the interest rate hedging instruments are designated and fully effective as cash flow hedges and movements in their fair value have been deferred in equity.