How to show negative value (infinity)

Hi Everyone,

I was using excel as a database. I create a measure that shows the percentage in -/+ when I transfer the database in SQL its shows only positive value, negative value show infinity error. but I need a negative percentage.

Please help me out.

thanks

Avg of PI variance SIM-Accessory = 
Var NullValue = "N/A"
Var _SIM = SUM(Combine_Data[PI Variances - SIM])
var _ACC = SUM(Combine_Data[PI Variances - Accessory])
Var _Combine = (_SIM + _ACC)
Var _Allowance = SUM(Combine_Data[1% Allowance Cost])
var _Percent = _Combine/[COGS]
Return  
IF(ISBLANK(_Percent),NullValue,_Percent)

SQL Version

Excel Version