[["", "2003", "2004", "2005"], ["risk-free interest rate", "2.92% ( 2.92 % )", "2.56% ( 2.56 % )", "3.87% ( 3.87 % )"], ["expected dividend yield", "2014", "2014", "2014"], ["expected option term in years", "5.0 years", "5.3 years", "7.5 years"], ["assumed stock price volatility", "85% ( 85 % )", "86% ( 86 % )", "84% ( 84 % )"]]