Calculate the number of periods for an annuity.
Annuity_NPER('rate', 'pmt', 'pv', ['fv'], ['type'])
|rate||Yes||double||The interest rate per period.|
|pmt||Yes||double||The payment made each period; it cannot change over the life of the annuity.|
|pv||Yes||double||The present value, or the lump-sum amount that a series of future payments is worth right now.|
|fv||No||double||The future value, or a cash balance you want to attain after the last payment is made.|
|type||No||int||The number 0 (the end of the period) or 1 (the start of the period), indicates when payments are due.|
Annuity_NPER(0.08/12, 500, -50000) Returns 165.34