^^ What they all said.
Plus tyres will make a difference and a lot of other factors including believe it or not, when your oil was last changed as you'll probably gain a few Bhp having fresh oil in over having old oil in.
If it does worry you though maybe it's worth getting the Zed put on a dyno just to give you some idea of where the power level is at or even a full health check (compression etc) just to make sure it's running as good as it should.