Evolution of the extent of the structures. The black dots with the gray area represent the longitudinal extent of the unperturbed CH plasma (HSS_u) and the red dots with the light red area are the longitudinal extent of the CIR/SIR (perturbed solar wind + HSS_p). The dark red lines represent the longitudinal extent of the entire CIR/SIR + HSS_u. The areas are the respective uncertainties. The purple line shows the extent of an area, that is bound by two Archimedean spirals, which are separated by 13.9° (CH1) and 30.9° (CH2).