A tailor must make $6$ of the same size suits for a client. The first suit took $14\mathrm{.}8$ hours to make and the last suit took $7\mathrm{.}9$ hours to make. What was the tailor's learning curve $\%$ of this run of suits assuming a steady state of production is never reached? Express your answer in $\%$ to the nearest $0\mathrm{.}1\%$