Day Trading Pre-market Open – 18 Apr 2019, page-10

That's tough question with the detail you provided.

A lot can happen in 2.5 years to totally transform a company.

If you look too far back you'll be using data that isn't relevant.

It can be different for each stock.

If it has been steady(ish), in any direction for 2 years then you'd be ok to use it.

Not really an answer but you'd have to provide the stock code on a case by case basis.