--Creating Table

Create Table Ex
(LossAmount int,
 Seq int Identity(1,1) )


--Inserting Sample Data

Insert Into Ex
Select 6087
Union ALL
Select 2605
Union ALL
Select 2308
Union ALL
Select 2278
Union ALL
Select 1770
Union ALL
Select 1060
Union ALL
Select 714
Union ALL
Select -3039
Union ALL
Select -3954
Union ALL
Select -6955
Union ALL
Select -7522
Union ALL
Select -8637
Union ALL
Select -9065
Union ALL
Select -11582
Union ALL
Select -13349
Union ALL
Select -14379
Union ALL
Select -17526
Union ALL
Select -17730
Union ALL
Select -21084


--Procedure For your Requirement

Create Procedure dbo.PercentileCalculator
@Percentile float
As
Begin
Declare @count int = (Select COUNT(*) From Ex)
Declare @PerValue Float
Set @PerValue = Round( ((@Percentile/100) * @count), 0)
;With CTE
As
(Select LossAmount, ROW_NUMBER() Over (Order By LossAmount) As rn From Ex)
Select * From CTE
Where rn = @PerValue
End


--Executing procedure

Execute dbo.PercentileCalculator 99.60