The yield curve is flat at $4\mathrm{.}38\%,$ and an investor trying to ride the yield curve buys a newly issued $5$ year bond at par with a $4\mathrm{.}38\%$ coupon. After a $1$ year holding period, the investor expects that the yield curve will still be flat but the yield will drop by $1\%.$ What is the expected $1$ year holding period return for the investor?

Enter answer in percents.