Im generally on during the times you mentioned, and it seems that there are a lot of flex group looking during that time. We also have quite a few flex teams that raid regularly. The best way to figure out what is going on in CTR around the times you are available is to create a tiny level one (block guild invites, cause you'll be bombarded) on Aerie Peak, and /join ctrlfg. That's generally where we look for more
It really varies from day to day as far as how much traffic it gets. On Tuesdays and Wednesdays its soooo crowded. But some Monday nights are a quite a bit less so.
Hope this help to answer your question!