In 1980 there were approximately 250,000 qualified defined benefit pension plans covered by the Pension Benefit Guaranty Corporation. By 2005, there are less than 80,000 qualified plans. Defined benefit plans continue to dwindle, becoming exception rather than rule. As 2011, only 10% of private employers offered pension plans, accounting for 18% of the private workforce. What reasons lead this situation happened? Explain.