Suppose that in a certain defined benefit pension plan: A) Employees work for 45 years earning wages that increase at a real rate of 2%. B) They retire with a pension plan equal to 70% of their final salary. This pension increases at the rate of inflation minus 1%. C) The pension is received for 18 year. D) The pension fund's income is invested in bonds which earn the inflation rate plus 1.5%. Estimate the percentage of an employee's salary that must be contributed to the pension plan if it is to remain solvent.