I think it depends on the sailing. If it's a really unique itinerary (like PC or TA), then there's likely to be a higher number of Pearl/Platinum cruisers, which means more slots taken up by them and less available for Gold and then Sliver. But if it's a standard sailing, it's more likely to be a 'mix' of CC statuses and a lot more first-timers. So there's less higher CC status passengers to take up all the slots, and more available when it comes time for Gold and Silver to book.