A tensile test uses a test specimen that has a gage length of $44$ mm and an area $109$ mm $2.$ During the test the specimen yields under a load of $122155$ N $.$ The corresponding gage length $54$ mm $.$ This is the $0\mathrm{.}2$ percent yield point. The maximum load $119508$ N is reached at a gage length $66$ mm $.$ Determine the engineering strain.