Hi, my 2007 525i (non sport) is only 11,000km, the brake is wearing so fast which is not equal to the mileage ? Also, the rear pad was wearing faster than the front.. I am a normal driver and most city driving... no speed ticket

The following is what I copy down from i drive..
Front 40,000 Rear 49,000--------------When Pick up Car
--------33,000-----38,000---------------5000km
--------28,000-----31,000---------------8000km
--------23,000-----23,000--------------11000km

Is this due to incorrect sensor reading or normal ? BMW Canada do not cover brake pad in the no cost maintenance program.