SQL Server 2012 :: Recurrent Balance That Resets When Hitting A Value

I have query that calculate a running balance, but I need to reset that balance when it reaches 240. Then start calculating the balance again from that value. For instance, let's see we have the following table:

YearAmmount
200049.95
200179.92
200279.92
2003114.99
2004120.00

[Code] ....

If I run the following query to get the running balance:

SELECT Year,
Ammount,
SUM(Ammount) OVER(ORDER BY Year ROWS UNBOUNDED PRECEDING) AS RunningTotal
FROM _YearlyTotals

I get:

YearAmmountRunningTotal
200049.9549.95
200179.92129.87
200279.92209.79
2003114.99324.78
2004120.00444.78

[Code] ....

I'm looking to reset the Running Total if it reaches 240, and continue calculating from there: Something like this:

YearAmmountRunningTotalAdjustment
200049.9549.9549.95
200179.92129.870.00
200279.92209.790.00
2003114.99240.00-84.78
2004120.00240.00-120.00

[Code] ....

Here is the code to create the table and insert data:

CREATE TABLE _YearlyTotals(
[Year] int NULL,
Amount numeric(18, 2) NULL
) ON [PRIMARY]
INSERT INTO _YearlyTotals([Year],Ammount) VALUES (2000,49.95)
INSERT INTO _YearlyTotals([Year],Ammount) VALUES (2001,79.92)

[Code] .....