Shown the number of years active, according to the actual games data

In some cases that could lead to wrong data. The reason is that its not forbidden to also add publishers of re-releases of a game. This leads to having games in the publishers game list that might originate from an earlier date where the publisher was not yet founded. So if its totally automatic and the editor cannot "overwrite" the data of the publisher/company starting year I don't really like it. Because I personally think that wrong data is worse than no data.

I agree. I'll fix making the company "founded" and "closed" date to take precedence if available.

This thing requires several chained changes. So far:

The company listings do shows a red asterisk when the starting years do not match
https://www.uvlist.net/companies/country/de

Releases per year chart highlights the years before the company foundation.
https://www.uvlist.net/companies/info/2440-THQ%20Nordic
This also handles the counting of the correct number of games "inside" the correct time period, necessary for subsequent evaluations

More changes:

"Active years" do not consider games made before the company foundation. Same for "Games per year"

If not marked as closed, a new "Last activity" reports the last year a game was made.

I've avoided so far similar considerations about games made after a company is officially closed.

New fix for very old companies, the active years are calculated from the first game if the foundation is before that date, like for the 161 years old MB
https://www.uvlist.net/companies/info/672-Milton%20Bradley