The mean and standard deviation (SD) of monthly returns, over a given period of time, for the stock markets of two countries, X and Y are:

Country Mean(%) SD(%)

X 1.57 4.87

Y 1.92 7.64

Assuming that the monthly risk-free interest rate is 0.25 percent, Calculate the Sharpe performance measures for each country. Which country has the best Sharpe performance measure. What does it mean?

I know how to calculate about Country X and Y but the last part of the question "what does it mean" make me really confused, I don't know what should I put it there?(the best is the best...)