Guild Wars 2

Hello all

I am making a spreadsheet to help me with my min/max calculations. I would like to know how damage boost traits and effects work.
From my stats I can calculate my average damage, but then I have a number of damage boosters to apply and I do not know if I should add them all or apply them one after an other.

For example
I am playing an elementalist, my damage boosters are:
- 2% per boon (5 boon on average) = +10%
- 10% when over 90% health
- 5% sigil on weapon
- 10% when attuned to air
- 4% from 4 stacks of vulnerability on average on my target
I am fairly confident vulnerability is applied last and affects your net output after all effects, but I am not sure.

Can anyone help me compute what my total damage boost is when at full health and attuned to air?

Thanks a lot!