21. Analysis of Net Debt Components of net debt (i)  Of the Group’s nominal fixed rate debt at 31 December 2012, €2,087 million (2011: €2,309 million) was hedged to floating rate at inception using interest rate  swaps. In accordance with IAS 39  Financial Instruments: Recognition and Measurement , hedged fixed rate debt is recorded at amortised cost adjusted for the  change in value arising from changes in underlying market interest rates and the related hedging instruments (interest rate swaps) are stated at fair value.  Adjustments to fixed rate debt values and the changes in the fair value of the hedging instrument are reflected in the Consolidated Income Statement. The  balance of nominal fixed rate debt of €2,444 million (2011: €2,137 million) pertains to financial liabilities measured at amortised cost in accordance with IAS 39. (ii)  Floating rate debt comprises bank borrowings and finance leases bearing interest at rates set in advance for periods ranging from overnight to less than one  year largely by reference to inter-bank interest rates (US$ LIBOR, Sterling LIBOR, Swiss Franc LIBOR and Euribor). CRH 99 As at 31 December 2012 As at 31 December 2011  €m Interest rate Weighted  average  fixed period  Years  €m  Interest rate Weighted  average fixed period  Years Interest-bearing loans and borrowings nominal - fixed rate (ii) (4,531) (4,446) Derivative financial instruments - fixed rate  1,314   2,010  Net fixed rate debt including derivatives (3,217) 6.3% 4.4 (2,436) 6.3% 6.3 Interest-bearing loans and borrowings nominal - floating rate (iii) (174) (289) Adjustment of debt from nominal to book value (ii) (210) (247) Derivative financial instruments - currency floating rate (1,162) (1,835) Gross debt including derivative financial instruments (4,763) 5.2% (4,807) 4.7% Cash and cash equivalents - floating rate  1,768   1,295  Liquid investments - floating rate  31   29  Net debt including derivative financial instruments (2,964) (3,483) As at 31 December 2012 As at 31 December 2011 Fair value  (i) including  share  of joint  ventures Book value  including  share of joint ventures Book value  excluding  share of joint ventures Fair value  (i) including  share of joint  ventures Book value  including  share of  joint ventures Book value  excluding  share of  joint ventures  €m   €m   €m   €m   €m   €m  Cash and cash equivalents (note 23)  1,768   1,768   1,747   1,295   1,295   1,246  Liquid investments (note 23)  31   31   -  29   29   1  Interest-bearing loans and borrowings (note 24) (5,249) (4,915) (4,808) (5,051) (4,982) (4,758) Derivative financial instruments (net) (note 25)  152   152   152   175   175   176  Group net debt (3,298) (2,964) (2,909) (3,552) (3,483) (3,335) (i)  The fair values of cash and cash equivalents and floating rate loans and borrowings are based on their carrying amounts, which constitute a reasonable  approximation of fair value. The carrying value of liquid investments is the market value of these investments with these values quoted on liquid markets. The  carrying value of derivatives is fair value based on discounted future cash flows at current foreign exchange and interest rates. The fair value of fixed rate debt  is calculated based on actual traded prices for publicly traded debt or discounted future cash flows reflecting market interest rate changes since issuance for  other fixed rate debt. The following table shows the effective interest rates on period-end fixed, gross and net debt: Net debt is a non-GAAP measure which we provide to investors as we believe they find it useful. Net debt comprises cash and cash equivalents, liquid investments,  derivative financial instrument assets and liabilities and interest-bearing loans and borrowings and enables investors to see the economic effects of these in total  (see note 22 for details of the capital and risk management policy employed by the Group). Net debt is commonly used in computations such as net debt as a %  of total equity and net debt as a % of market capitalisation.