def zip
      return nil unless zip5 && !zip5.empty?
      [zip5, zip4].select { |z| z && !z.empty? }.join('-')
    end
def zip
      return nil unless zip5 && !zip5.empty?
      [zip5, zip4].select { |z| z && !z.empty? }.join('-')
    end
Complete zip code.
 Returns a 9-digit Zip Code, when available.