Rear Brake Disc Wear

[Hudsonia9]

I noticed a rubbing sound from the rear brake on my 01 tiger 70,000km on clock,on close inspection the disc is lightly scored and has worn maybe 1mm from the body of the rotor,leaving a lip on the outside edge.Plenty of meat left on the pads,but look very bronze.Is this wear fairly normal given the milage,am i up for a new disc rotor,or is there another course of action ie have the disc skimmed,this would reduce the thickness to around 4.5 mm.Any advice would be appreciated.