A geochemist measures the concentration of 28.4 salt dissolved in Lake Parsons and finds a concentration of . The geochemist also measures the concentration of salt in several nearby non-isolated lakes, and finds an average concentration of . Assuming the salt concentration in Lake Parsons before it became isolated was equal to the average salt concentration in nearby non-isolated lakes, calculate the percentage of Lake Parsons which has evaporated since it became isolated. Round each of your answers to significant digits.