School project on how the music industry has changed from the internet

Pretty much what the title says.

I was wondering the quarterly sales on itunes compared to the quarterly sales at a store that distributes CDs, like FYE, best buy etc.

Also, I was wondering if anyone knows how much percentage of the sale the music industry gets from a CD sale compared to an Itunes song sale.

Finally, I was wondering the amount of music being pirated illegally on programs like limewire every year.

Thanks. It would help.
Do some research. Sales figures get published, as do studies into use of various technologies. A little googlemancy and wikiing and you've got all you need.