Information on numbers of slaves transported from the C16th to C19th in the Atlantic Slave Trade. Some of the numbers look a little too precise to be exactly reliable. Interesting though.
This is a very interesting and unusual idea. Historians at Stanford have collected very specific and detailed information about historical events within short time frames and then produced graphic representations of these events that you can play over maps. It's very precise and perhaps too detailed for many high school level students to make sense of, however some of them helped show how historical phenomena occurred. Particularly chilling was the graphic showing slave purchases in the Rio slave market in the mid-C19th; you can see individual children being bought at specific times by specific people.