This info does not tell us, however, what documents are most valuable . That is, what we would cache if we had a choice. Here are the same pictures, but relative contribution is shown. Savings Here are savings on per-type basis. Quite an interesting picture.
Images are well ahead.
Surprisingly, ratios for other document types are pretty close. This probably means that one should cache images first, but for other objects, the type does not matter much. Most of the data saved so far comes from images.