William Meyer bought a used car for $6,500 two years ago. He spent $1,299 for gas, $160 for oil changes, $209 for maintenance, and $200 for two new tires. He paid $657 for insurance and $158 for registration and licenses. He calculates the car has depreciated by about $2,100. William also drove the car a total of 16,789 miles and estimates that its present value is $4,400. What was the cost per mile for William to operate and maintain his car?