Class B Invested Amount means, on any date of determination, an amount equal to (a) the Class B Initial Invested Amount, minus (b) the aggregate amount of principal payments made to the Class B Certificateholders prior to such date, minus (c) the aggregate amount of Class B Investor Charge-Offs for all prior Distribution Dates, minus (d) the amount of Reallocated Principal Collections allocated on all prior Distribution Dates pursuant to subsection 4.08(a) (excluding any Reallocated Principal Collections that have resulted in a reduction in the Collateral Invested Amount pursuant to Section 4.08), minus (e) an amount equal to the amount by which the Class B Invested Amount has been reduced on all prior Distribution Dates pursuant to subsection 4.06(a) and plus (f) the amount of Excess Spread and Excess Finance Charge Collections allocated and available on all prior Distribution Dates pursuant to subsection 4.07(e) for the purpose of reimbursing amounts deducted pursuant to the foregoing clauses (c), (d) and (e); provided, however, that the Class B Invested Amount may not be reduced below zero.