Model tweaks

Hi guys, thanks for developing this nice model. Here are some tweaks. 
Nice chatting with you Jarod :)
I think changing 'Interest' to 'Indexation' makes this model less user friendly. I think we should at least be more specific than 'Indexation'. Previously this was called 'Interest rate as ten year bond rate' but we agreed it was too long. 'Interest paid' isn't the best title for this slider, but I'm not convinced 'Indexation paid' is better.