Most popular per month

Hey! The client has a set of 50 images that keep rotating everyday and when a user clicks one of those images he is taken to that images site, in the background (database) i maintain a counter _for the day_ and then display the top ten images everyday in this format: 1-10 before the next days counter starts this data is stored in a table which has a simple structure like this img_id1 int,img_id2 int (etc till img_id10) Now the client wants a little extra functionality, and with me sucking at maths I need some help please, basically he now wants to have a chart with all the 50 images there and showing _via percentages_ instead of the present 1-10 display which ones are the most popular till date. example: 1. image name: (percentage here) 2. image name: (percentage here) 3. image name: (percentage here) etc any ideas on where i can start/ code tips/ urls etc would be most appreciated. Also, if i am not mistaken there was some charting software to display this kind of data in pie and line charts... anybody know what i am talking about? because i cant find such a link in my bookmarks. Thanks in advance, Ryan