(Gains and Losses, Corridor Amortization) Vickie Plato, accounting clerk in the personnel office of Streisand Corp., has begun to compute pension expense for 2012 but is not sure whether or not she should include the amortization of unrecognized gains/losses. She is currently working with the following beginning-of-the-year present values for the projected benefit obligation and market-related
values for the pension plan:

The average remaining service life per employee in 2009 and 2010 is 10 years and in 2011 and 2012 is 12 years. The net gain or loss that occurred during each year is as follows. (In working the solution, you must aggregate the unrecognized gains and losses to arrive at year-end balances.)

You are the manager in charge of accounting. Write a memo to Vickie Plato, explaining why in some years she must amortize some of the net gains and losses and in other years she does not need to. In order to explain this situation fully, you must compute the amount of net gain or loss that is amortized and charged to pension expense in each of the 4 years listed above. Include an appropriate amortization schedule, referring to it when ever necessary.