Electricity generating plant is typically built within $5$ years with uniformly distributed expenditures per each year. A new construction schedule is considered in which the plant will be built within $4$ years with uniformly distributed expenditures. The sum of expenditures in both cases will be the same.

Calculate the change of capital cost in percent using the original schedule as a reference.

Use the following pattern for the answer: answer $=($Co$-$Cn$)/$Co $*100(\backslash \%),$

where:

Co $-$ original schedule cost $(5-$year build$)$

Cn $-$ new schedule cost $(4-$tear build$).$

The interest rate in both cases is the same and equal to $\backslash (9\backslash \%\backslash ).$

Use the end of construction as the reference time point

Answer $=$