Recursive Calculation, Sql Server

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CREATE TABLE Deals
(
	MyKey varchar(50)
   ,Outstanding float 
   ,Rate float
)
INSERT INTO Deals VALUES
('Key1', 100000, 1.25),
('Key2', 500000, 3.55)

CREATE TABLE Amortization
(
	MyKey varchar(50)
   ,AmoDate datetime
   ,PaymentAmount float 
)
INSERT INTO Amortization VALUES
('Key1', '2015-06-01', 1000),
('Key1', '2015-07-01', 3000),
('Key1', '2015-08-01', 5000),
('Key1', '2015-09-01', 1000),
('Key1', '2015-10-01', 2000),
('Key1', '2015-11-01', 1000),
('Key2', '2015-06-15', 10000),
('Key2', '2015-09-15', 23000),
('Key2', '2015-12-15', 50000),
('Key2', '2016-03-15', 13000),
('Key2', '2016-06-15', 32000),
('Key2', '2016-09-15', 11000)

;WITH IncrementingRowNums AS
(
	SELECT d.MyKey
		  ,d.Outstanding
		  ,d.Rate
		  ,AMO.PaymentAmount
		  ,AMO.AmoDate
		  ,ROW_NUMBER() OVER (ORDER BY d.MyKey, AMO.AmoDate ASC) AS RowNum
	  FROM Deals d
	 INNER JOIN Amortization AMO
		ON d.MyKey = AMO.MyKey
),	 
lagged AS
(
	SELECT MyKey 
	      ,Outstanding AS new_outstanding
	      ,Rate
	      ,PaymentAmount
	      ,AmoDate
	      ,RowNum
	  FROM IncrementingRowNums
	 WHERE RowNum = 1
  UNION ALL
	SELECT i.MyKey
	      ,(l.new_outstanding - l.PaymentAmount) 
	        * (1 + i.Rate * (DATEDIFF(DAY,l.AmoDate, i.AmoDate)/365.25))    
	         AS new_outstanding
	      ,i.Rate
	      ,i.PaymentAmount
	      ,i.AmoDate
	      ,i.RowNum
	  FROM IncrementingRowNums i
	 INNER JOIN lagged l
	    ON i.RowNum = l.RowNum + 1
)	 
SELECT *
  FROM lagged	 
  OPTION (MAXRECURSION 500)

View schema
Execution time: 0,03 sec, rows selected: 12, rows affected: 14, absolute service time: 0,19 sec