P2.11 In 1970, the year the Clean Air Act was passed by the U.S. Congress, the average hydrocarbon emission was about 14 grams per mile traveled. That number dropped to about 1 gram per mile by the year 2000. The total number of motor vehicle miles traveled increased in the same period from about 1100 billion miles in 1970 to about 2600 billion miles in 2000. Calculate the total hydrocarbon emissions in 1970 and in 2000, in tons. What is the percent increase or decrease over the 30-yt period?