Here is a compilation of all challenge series results, from 2008 to the current ongoing 2018 challenge series.
Please, do point out any errors you find in the tables.
PrimeGrid Challenge Series Results
The files are in a free webhost.
The site goes down for one hour every day.
So, if you can't access it, wait and try again later.
"Accidit in puncto, quod non contingit in anno."
Something that does not occur in a year may, perchance, happen in a moment.