Does anyone know how to write an expression in Qliksense to formulate a Ratio?

[#1]

I'm looking to work out a percentage in the expression box, Qliksense doesn't believe its right but I'm fully convinced it's fine

Count({[MUDID] [WHERE] [Logged In?] / (Count [MUDID]) = ["Yes"] * [100]})

[#2]

Ok thanks