Use CSS and HTML to create a bar graph. Mine looks like the image shown at the right (only the top is visible). You can use any real data you like, or you can make some up. (You should be clear if it's real or not, either because the the title is silly, or by just saying so.) You may do what you like, under the following:
Don't feel like you need to follow my layout exactly. There are other places to put the numbers, and all sorts of more interesting labeling might be possible.
I made the bars with divs inside divs. The outer divs are the same length, and the inner is a percentage reflecting the underlying data.
If you want to make a graph with vertical bars instead, feel free.
When you're ready, post your page on Sandbox, then go here and enter the URL of the page.