An electrostatic precipitator for a coal-fired power plant has an overall particulate recovery of 95%. The company engineer decides that this is too good, that it is not necessary to be this efficient, and proposed that part of the flue gas be bypassed around the electrostatic precipitator so that the recovery of fly ash (particulates) from the flue and gas would only be 85%. What fraction of the flue gas stream would need to be bypassed?