A tensile test uses a test specimen that has a gage length of $48$ mm and an area $139$ mm $.$ During the test the specimen yields under a load of $76337$ N $.$ The corresponding gage length $55$ mm $.$ This is the $0\mathrm{.}2$ percent yield point. The maximum load $170236$ N is reached at a gage length $67$ mm $.$ The fracture occurs at a gage length of $67\mathrm{.}3$ mm and the specimen necked to an area $\backslash (=92\backslash$mathrm$\{$~mm$\}\backslash ).$ Determine $\backslash \%$ reduction of area.