Allowable (a₉, e₉) space for Planet 9 with m₉ = 10 m_⊕ (left-hand column) and 5 m_⊕ (right-hand column), at representative inclinations i₉ = 15°, 20° and 30°. The color represents the relative angle between the expected mean plane of the 100 <  a <  200 AU Kuiper belt and IP8. The black curve demarcates the upper limit of deduced from the known KBOs: on the right side, the colorful regions with are the most probable zones for Planet 9; while on the left side, the gray regions with are less likely since the perturbation from Planet 9 seems too strong. The white regions indicate the zones with q₉ − a <  10 AU, where our theoretical approach for calculating may fail due to strong interactions between the KBOs and Planet 9.