How to write percent change in variable

#1

How would I write decreased by 5% into a varaiable?

I know 10% is 1.1 but 0.5 for 5% does not seem to be working

I am successfully using
set variable increasedHumidity = {baselineHumidity}*1.1
But I can’t figure this one out.
set variable increasedHumidity = {baselineHumidity}*5%

Thanks

#2

{baselineHumidity}*1.05 ?