A mixture consisting of only sodium chloride (NaCl, 58.44 g/mol) and lithium chloride (LiCl, 42.391 g/mol) weighs 1.9023 g. When the mixture is dissolved in water and an excess of silver acetate is added, all the chloride ions associated with the original mixture are precipitated as insoluble silver chloride (AgCl, 143.32 g/mol). The mass of the silver chloride is found to be 5.5109 g. Calculate the mass percentage of sodium chloride in the original mixture.