Risk-Free Rate and CAPM Expected Return

In the CAPM the expected return of an asset is $E[R]=r_f+\beta\,(E[R_m]-r_f)$. The expected return of the market portfolio is fixed at $E[R_m]=8\%$. An asset has $\beta=0.5$.

The risk-free rate rises from $2\%$ to $4\%$ while $E[R_m]$ stays at $8\%$. By how much does the asset's CAPM expected return change? Give the change as a decimal (e.g. $0.01$ for one percentage point).