counterparty to a fnancial instrument fails to meet its contractual obligations and arises principally from the Association s receivables from customers and cash deposits T rade and other receivables The Association s e xposure to credit risk is infuenced mainly by the individual characteristics of each customer New customers are generally analysed individually for creditworthiness before credit is ofered The Association establishes an allowance for impairment that represents its estimate of incurred losses in respect of trade and other receivables The main components of this allowance are a specifc loss component that relates to individually signifcant e xposures and a collective loss component established for groups of similar assets in respect of losses that have been incurred but not yet identifed The collective loss allowance is determined based on historical data of payment statistics for similar fnancial assets Impairment losses The aging of trade receivables at the reporting date was Gross 2018 I mpairment 2018 Gross 2017 Impairment 2017 Not past due 030 days 21603 20 262 P ast due 3160 days 13365 P ast due 6190 days P ast due 91 days 27 500 TOT A L 34968 47 762 b Mark et Risk Mark et risk is the risk that changes in mark et prices such as foreign e x change rates interest rates and equity prices will afect the Association s income or the value of its holdings of fnancial instruments The objective of mark et risk management is to manage and control mark et risk e xposures within acceptable parameters while optimising the return Interest R ate Risk Interest rate risk s are limited to the impact of changes in interest rates on income earned on cash and term deposits Interest rate risk represents the only signifcant mark et risk of the Association A t the reporting date the interest rate profle of the Association s interestbearing fnancial instruments was Carrying Amount 2018 2017 V ariable rate instruments Cash at bank 587 496 362465 Fix ed rate instruments T erm deposits 3 100 000 3 150 000 With respect to cash at bank a change of 100 basis points in interest rates would increase or decrease the proft and loss by 5875 2017 3625 The fair value of fnancial assets and liabilities appro ximate their carrying value at yearend c Liquidity Risk Liquidity risk is the risk that the Association will encounter difculty in meeting the obligations associated with its fnancial liabilities that are settled by delivering cash or another fnancial asset The 45 AMEC R eport 2018 OPERA TIONAL AND FINANCIAL REPOR T NO TES T O AND FORMING P AR T OF THE A CCOUNT S