For my information, I went and looked at the most recent booking thread. I counted (with minimal mistakes, I hope) and I have rounded the numbers in relation to Castaway Club status.
We will assume for argument, although, I'm sure it's not true, that someone that reported a price, booked the cruise.
Platinum - 70
Gold - 125
Silver - 160
Interesting that the cruisers with the youngest relationship with Disney reported the most prices.
Something to keep in mind with those numbers is the quantity of pool to pick from diminishes with the exclusivity of the status.
I would be willing to bet that the percentages relative to the total in each group is pretty close.