Young's modulus from graph

In an experiment to determine the Young's modulus, steel wires of five different lengths (1,2,3,4, and 5m) but of same cross section (2mm2) were taken and curves between extension and load were obtained. The slope (extension/load) of the curves were plotted with the wire length and the following graph is obtained. If the Young's modulus of given steel wires is x×1011Nm−2, then the value of x is _________.