In 1960, the average price for such a diamond stood at some 2,700 U.S. dollars. Since then, the diamond price has increased more than tenfold, to 29,650 U.S. dollars in 2015. If the price for per carat diamond continues rising at the same average annual rate, at which it's been increasing between 1960 and 2015 (Hint: this is your Step #1!), it will reach $80,000 per carat after another years