Wiring is chosen for its environment: temperature, water and humidity, solid foreign bodies, corrosive substances, mechanical damage, vibration, flora, fauna, solar radiation and thermal insulation. Mechanical damage is minimised by the wiring's own characteristics, location or added protection. Cables passing through bulk thermal insulation are rated per AS/NZS 3008.1 by the length inside it: up to 150 mm as touching a surface, over 150 mm to 400 mm as partially surrounded, over 400 mm as completely surrounded.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.