negative number in brackets

I have a text object that I wanna show as number with % and when it´s negative I wanna it in brackets.

It works if the result is +20.29%, but if the result is (8.85%) it shows (0.09%)

The expression is as below:

=num((

max(Aggr(

(sum({<[Reporting Calendar Year] = {'$(vCurrentYear)'}>} $(vCurrency)) - sum({<[Reporting Calendar Year] = {'$(vPriorYear)'}>} $(vCurrency)))

/

sum({<[Reporting Calendar Year] = {'$(vPriorYear)'}>} $(vCurrency)),

[Broker Pack Region]))

-

max(Aggr(

(sum({<[Reporting Calendar Year] = {'$(vPriorYear)'}>} $(vCurrency)) - sum({<[Reporting Calendar Year] = {'$(vPriorYearBefore)'}>} $(vCurrency)))

/

sum({<[Reporting Calendar Year] = {'$(vPriorYearBefore)'}>} $(vCurrency)),

[Broker Pack Region])))*100

,'+ ###.##%;(###.##%);-')

Any idea what to do?