Audience creation: as fast as possible or not depending on attributes?

Rookie Contributor

Hi all, 

I have been looking for an answer on the following question: 

When I create visitor attributes, is the information saved in the attributes themselves? 

Meaning, if I create an audience, let's say, 2 months after I created the attributes, will the audience contain the information of these last two months? Or does is only start collecting information from the day you create the audience? 

Would like to know this to keep audiencestream as clean as possible and avoid an overload of audiences.

Thanks in advance!

Lara vandooren