Your Grandfather left you $555,079 in his will. You have decided that you wanted to invest that money, and not touch it until it has grown to $1,000,000. If you believe you can earn 8.40% per year on your investment portfolio, how long will it take for your original investment of $555,079 to turn into $1,000,000 ? (Please respond in years, with two significant decimal points - e.g. 8.45 for 8.45 years)