How much of the bandage or splint is legally obligatory to cover during wiping?

Wiping over Bandages, Splints, and Plasters (المسح على الجبيرة)

• Wiping the entire bandage completely
• Wiping the majority (more than half) of the bandage
• Wiping exactly one-quarter of the bandage
• Wiping only the edges of the bandage