100% sure - I wouldn't miss it!
81-99% sure - I'm just trying to sort out travel plans or babysitters.
I need more information before I can make that decision.
51-80% sure - I'm still waiting to see who goes.
1-50% sure - I really want to go, but it's not looking likely.
0% - I know I won't be able to attend, but I send everyone my regards.