how to use indicator in ssrs?

Hi Guys 

Thanks for help.

I want to use indicator in SSRS .

here is my requirement scenario below:

i have already one Month to Date dataset and i am using matrix on it. It has two column (count no & percentage) .

it has also two row groups and one column groups. Percetange column calculated base on count /group total.

now i want to use indicator for that 

i need to compare last 90 days percentage with Month to Date percetage. if you it is increase than i have show up indicator and if it is decrease than down indicator.

Please help me how can do this?

it is very urgent.

Thanks

Vik ..