How now to achieve the same results? This is not realistic Maybe it's worth it to show the best result in the last year?

You make it sound like those scores are somehow not fair or not achievable anymore. Which, I can assure you, isn't true since I personally verified it. Gelidis is a highly skilled player and he managed to play that game almost flawlessly. And there were no significant changes in game mechanics since that time so anyone can get close to that score or even beat it if he puts enough effort into it.

Sadly we weren't keeping savegames back then but Gelidis recorded his gameplay once: https://www.twitch.tv/videos/10613074 Unfortunately there was a bug in the game at the time when this particular video was recorded. Nothing too major (you probably won't even notice it) but I still had to reset that score. But other games weren't affected by the bug, so scores are perfectly valid. And overall tactics he used in that video is still good, if you can repeat it you'll get about 40k for sure.

But regardless of that I still like the idea of having a separate scoring tables for different time periods, so I may add it sooner or later. But in no way it will mean throwing away and forgetting old scores and achievements.