Dexter Construction Corporation is building a student condominium complex; it started construction on January $1,$ Year $1.$ Dexter borrowed $$2\mathrm{.}5$ million on January $1$ specifically for the project by issuing a $10\%,5-$year, $$2\mathrm{.}5$ million note, which is payable on December $31$ of Year $3.$ Dexter also had a $12\%,5-$year, $$3$ million note payable and a $10\%,10-$year, $$1\mathrm{.}8$ million note payable outstanding all year. Calculate the weighted average interest rate on the non$-$construction$-$specific debt for Year $1.$