3% is an average ctr. There is no such thing as too high ctr. Google is fine with any ctr as long as your traffic is good and there is no click fraud
As far as google is concerned, therei s no such thing called 'normal' or acceptable CTR. It can vary as you please as long as there is no click fraud.
It doesn't matter hows you CTR when the users come from worldwide then no tension .Just use our services
Google has its own rules and no one knows them correctly but according to my knowledge it is quite good.