My guess is, you would keep 90%. They don't have a pdf grid. They do give it to you if you click on cancellation policy (based on your dates) when you book. You can click on cancel (it won't cancel with the first click but it can be scary to do if you are unsure about cancelling). They will tell you what you lose and what you keep. You then have the option to keep the reservation or cancel the reservation.
I just did it with one I don't want to cancel. It is 165 days out and used 19 trading power. If I cancel today I lose 2 tpu's get back 17 and lose my $239 exchange fee.