If the nominal rate of return is $10\mathrm{.}87\%$ and the inflation rate is $5\mathrm{.}66\%,$ by what percent is actual purchasing power increasing?

Enter your answer as a percentage with four decimal places but without the percent symbol. For example, if your answer is $90\mathrm{.}1234\%,$ enter $90\mathrm{.}1234$