These are the topmost point (1, 100) by definition, and the rightmost point (poorest people, lowest wealth) or (p=100, w=0) or (100, 0). This unfortunate rightmost point is given because there are always at least one percent of households (incarcerated, long term illness, etc.) with no wealth at all. Given that the topmost and rightmost points are fixed ... our interest lies in the form of the WOP curve between them.