A student from China starts their second year at the University of Chicago. Last years tuition cost the student 310,697 (yuan) but this year her tuition cost her 307,697 (yuan). What has happened to China's currency?

• The yuan has barely decreased against the U.S. dollar in a year.
• The yuan has depreciated against the U.S. dollar in a year.
• The yuan has appreciated against the U.S. dollar in a year.