Gaia's guild system is -very- bad. So you're likely only seeing a fraction of the actual threads in this forum.
To fix this, add &start=40 to the end of the URL or address of the year you're looking at. This lets you read the bugged, hidden page 2.
&start=60 = page 3, &start=80 = page 4, etc until there is no more pages.
This stems from a bug in guilds where dated threads have a habit of hiding any content after the first page's fill of topics. At the moment, there's no discernible way of fixing this, and it tends to plague larger guilds with older content.