A stock was trading at $122.90 at the end of year 1. It was trading at the end of year 2 at $116.20 immediately after giving a dividend of $4.60. At the end of year 3. it was trading at $126.40 immediately after giving a dividend of $4.80. Finally, it was trading at $136.50 at the end of year 4 without giving out any dividend. What was the arithmetic average annual return of this stock for the three years between years 1 and 4? options: 6.24% 6.40% 6.56% 6.72% 6.88%