Good question, there are many links and some people offer to provide spreadsheets with market data, which, quite frankly , is done from their own analysis of market data, if not done from someone else which gives it to them.
I know that I would have to make my own data from their work if I used it.
https://oldforums.eveonline.com/?a=channel&channelID=3514
https://oldforums.eveonline.com/?a=topic&threadID=1107558
Science and Industry Resource thread
https://oldforums.eveonline.com/?a=topic&threadID=1107558&page=1#3
Guides and Tutorials
Spreadsheets
One more thing, save the data offline and don’t count on it being online.
You’re never best served but by yourself.
In other words, if you don’t do it yourself, either no one else will, or , someone else will have to (like, if you delegate powers).
Just because someone is keeping an online database for 10 to 15 years doesn’t mean that he doesn’t work harder than others to do it.
Also, if you do some work for it yourself, such as protecting some of the security of the data by saving it offline or on your own system, without breaking his rights, then, you can help him, and you can help yourself.