You are tasked with analysing the historical performance of two shares, Share A and Share B, over a 6-year period. Below is a table of annual returns for each share.
Year                Share A Return (%)              Share B Return (%)
1                                 10%                                  12%
2                                   8%                                    9%
3                                   -5%                                 -4%
4                                  15%                                18%
5                                   -2%                                   0%
6                                   12%                               14%

Required:
1 Calculate the average annual return and standard deviation of returns for both Share A and Share B.
2 Explain the concept of standard deviation in the context of risk and return analysis.
3 Based on your calculations and understanding of risk and return, which of the two shares, Share A or Share B, is more volatile over the 6-year period? Provide a rationale for your answer.