How can I calculate that? Is there any formula for this calculation or what should i do?

Question 12 0.5 out of 0.5 points The following one-year "forward" rates exist for each of the years 2012-2016: 1/1/12 - 31/12/12 20.00% 1/1/13 - 31/12/13 25.00% 1/1/14 - 31/12/14 20.00% Unit Menu 1/1/15 - 31/12/15 20.00% 1/1/16 - 31/12/16 11.11% Calculate the 1, 2, 3, 4, and 5 year spot rates as at 1/1/12. Accuracy to two decimal places is required. Selected Answer: 1-year rate = 20% 2-year rate = 22.47% 3-year rate = 21.64% 4-year rate = 21.23% 5-year rate = 19.14% Answers: Cannot be calculated as more information is required. 1-year rate = 20% 2-year rate = 22.47% 3-year rate = 21.64% 4-year rate = 21.23% 5-year rate = 19.14% 1-year rate = 20% 2-year rate = 25% 3-year rate = 20% 4-year rate = 20% 5-year rate = 11.11% 1-year rate = 20% 2-year rate = 22.50% 3-year rate = 21.67% 4-year rate = 21.25% 5-year rate = 19.22%