This is the simple answer since you can find those articles about spam and how many emails they send a day. Take that, the population that has access and I get 98% spam email being sent per day.
Remember this is your research and not mine. I will not vet or backup my claim. That's your job.
Links? Google is the tool I used. Since you must do your own study what I've read over the years is not for your report.
Bob
How much server space is advertisements and spam?
I am doing a project over the evolution of the internet, and I cannot seem to find this anywhere.
I am pretty sure this is in the wrong place, but I don't know where else to put it.
I would also like some links if you can find them. Thanks!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic