A businesswoman wants to determine the difference between the costs of owning and leasing an automobile. She can lease a car for $460 a per month (on an annual basis). Under this plan, the cost per mile is $0.02. If she were to purchase the car, the fixed annual expense would be $4600, and other costs would amount to $0.06 per mile. What is the least number of miles she would have to drive per year to make leasing no more expensive than purchasing?