190 NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS OF AEGON N.V.  NOTE 26 - 27 AEGON The Netherlands also has a post-retirement medical  plan that contributes to the health care coverage of employees  and beneficiaries after retirement. The liability related to this  plan amounted to EUR 46 million at December 31, 2010  (2009: EUR 45 million). Assumptions used to determine benefit obligations at year-end: AEGON UK operates a defined benefit pension scheme  providing benefits for staff based on final pensionable salary.  The assets of the scheme are held under trust separately from  those of the Group. The assets of the scheme are held in  policies affected with Scottish Equitable plc. The scheme is  closed to new entrants. Under IAS 19, the defined benefit plan  has a deficit of EUR 247 million at December 31, 2010 (2009:  EUR 339 million). For each asset class, a long-term return assumption is derived  taking into account market conditions, historical returns (both  absolute returns and returns relative to other asset classes) and  general forecasts for future returns. Government bonds are  taken as providing the return with the least risk. The expected  long-term rate of return is calculated as a weighted average of  these assumed rates, taking account of the long-term strategic  allocation of funds across the different classes adopted by the  trustees of the scheme. AEGON UK  Assumptions used to determine benefit obligations at year-end: 2010 2009 Discount rate 5.40% 5.70% Salary increase rate 4.40% 4.90% Pension increase rate 2.60–3.30% 3.60% Price infl ation 3.40% 3.60% Expected long-term return on assets 6.00% 6.40% 2010 2009 Discount rate 5.30% 5.75% Salary increase rate 2.50% 2.50% Social security increase rate 2.50% 2.50% Pension increase rate 2.00% 2.00% Health care cost trend rate assumed for next year 0.00–2.00% 1.50–2.00% Rate that the cost trend rate gradually declines to 0.00–2.00% 1.50–2.00% Year that the rate reaches the rate it is assumed to remain at N.A. N.A. 2010 2009 Discount rate 5.25% 5.30% Social security increase rate 2.50% 2.50% Pension increase rate 2.00% 2.00% Assumptions used to determine net periodic benefits costs for  the year ended December 31, 2010: