Tracking visitors to a website

for the course of several years.......is there a way to do that? I know that alexa and http://sitebehindytics.compete.com are two good sites, but they only show the course of one year not more than that. Any way to see it multi year?

I`m curious cuz I`d like to see how GC has been doing the past 3 years in terms of unique visitors.