An experimenter uses a Hall probe to measure the internal magnetic field magnitude \(B\) of an air-core toroidal solenoid carrying a constant current of \(I = 2.0\text{ A}\). The measurements are taken at various radial distances \(r\) from the central axis of symmetry within the core, and the resulting data are plotted as \(B\) versus \(1/r\) in the graph shown. Based on the graph, what is the total number of turns \(N\) of wire on the toroid?