Calculated Field Pivot Table

[Excel1991]

Hello All,

I am trying to create a calculated field in a pivot table so that i can find the variance between the current years beginning account balance and the prior years ending account balance.

[TABLE="width: 500"]
<tbody>[TR]
[TD]A[/TD]
[TD]B[/TD]
[TD]C[/TD]
[TD]D[/TD]
[TD]E[/TD]
[TD]F[/TD]
[TD]G[/TD]
[TD]H[/TD]
[TD]I[/TD]
[/TR]
[TR]
[TD][/TD]
[TD]1999[/TD]
[TD]1999[/TD]
[TD]2000[/TD]
[TD]1999-2000[/TD]
[TD]2000[/TD]
[TD]2001[/TD]
[TD]2000-2001[/TD]
[TD]001[/TD]
[/TR]
[TR]
[TD][/TD]
[TD]Beginning Balance[/TD]
[TD]Ending Balance[/TD]
[TD]Beginning Balance[/TD]
[TD]VARIANCE[/TD]
[TD]Ending Balance[/TD]
[TD]Beginning Balance[/TD]
[TD]VARIANCE[/TD]
[TD]Ending Balance[/TD]
[/TR]
[TR]
[TD]1[/TD]
[TD]1000[/TD]
[TD]1500[/TD]
[TD]2000[/TD]
[TD]=D1-C1[/TD]
[TD][/TD]
[TD][/TD]
[TD]=G1-F1[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]2[/TD]
[TD]0[/TD]
[TD]500[/TD]
[TD]500[/TD]
[TD]=D2-C2[/TD]
[TD][/TD]
[TD][/TD]
[TD]=G2-F2[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]3[/TD]
[TD]100[/TD]
[TD]500[/TD]
[TD]800[/TD]
[TD]=D3-C3[/TD]
[TD][/TD]
[TD][/TD]
[TD]=G3-F3[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]4[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
</tbody>[/TABLE]

I do not know how to have to calculate the field so that I can subtract the previous years ending balance from the current years starting balance. Theoretically you would think that whatever you left off with last year SHOULD be your starting balance in the current year; however, that is not that case so I want to illustrate the variance for each line item.

I know I could copy and paste and do this manually, but I would like it in a pivot so that I can include a slicer-by year. This way i can sort the pivot from largest variance to smallest variance and just cycle through the years to get a feel for which line items are causing the variance.