Please help!!! I'm super confused!

Ok, here's the deal. I had the following math problem:

In 1997-41,344 motor vehicle production in countries outside the United States.

In 1950-2,571 motor vehicle production in countries outside the United States.

What was the percentage increase in motor vehicle production in countries outside

the United States from 1950 to 1997?

I took 41,344 and subtracted 2,571, this gave me a difference of 38,773.

I then took the 38,773 and divided it by 2,571, this gave me 15.08.

I then moved the decimal two places to the right which gave me a total of 1,508%.

My teacher is telling me this is wrong. She said the answer is 15.08% because when you divide the two the answer is all ready in percent form.

Is this right? I thought when you divided it was in decimal form and you had to convert it to a percent???????? Please help, All other probelms I have done this way were right but for some reason this one she says is wrong. Why would this all ready be in percent form if all other problems I do are not?:confused: :confused: :confused:

Thank you for any help you have on this matter.

Julie