2002 2001 2000 Dividend yield .41% .38% .48% Volatility 49% 51% 51% Risk-free interest rates 2.0 – 5.2% 3.6 – 5.4% 5.1 – 6.4% Expected life (years) – stock option plans 4.9 – 8.4 5.2 – 8.5 5.6 Expected life (years) – stock purchase rights plan 1 1 1 Weighted average fair value of stock options granted during the year $ 13.45 12.68 9.81 Weighted average fair value of stock purchase rights $ 7.88 8.79 8.95 59 expd 02 Note 5 The fair value of each option grant is estimated on the date of grant using the Black- Scholes option pricing model with the following assumptions used for grants: