User blog comment:Maopyon/Using References and Citations on ALL questionable information (especially on the trivia section)/@comment-24097713-20131207023243/@comment-131168-20131209200506

As you say, the indies charts don't go far back, so no use trying to use them as a permanent source. The daily rankings don't seem to go back very far, either. Maybe someplace archives them?

The weekly data for major releases goes back to September 2005, though. Here are tables with links for CD Singles and CD Albums categories.