38.2% is wrong. Can u solve this for me?

Problem 7-8 Standard deviation of returns The following table shows the nominal returns on Brazilian stocks and the rate of inflation. Year 2012 2013 2014 2015 2016 2017 Nominal Return (%) 0.1 -17.0 -15.0 -41.5 66.3 27.0 Inflation (%) 5.9 6.0 6.5 10.8 6.4 3.0 a. What was the standard deviation of the market returns? (Use decimals, not percents, in your calculations. Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.) Standard deviation 38.20 %