In 2009, Internationale Outstanding University (IOU) had an enrollment of 25,236 undergraduates, each of whom paid $6,406 per year in tuition. In 2010, enrollment was 26,270 students, and tuition was raised 4.6%. In 2011, IOU received $186.8M in revenue from student tuition, and enrollment was 26,242 students. In 2012, it is estimated that tuition will be $6,920 and IOU needs to receive 6.3% more total revenue from tuition than in 2011.

What was the tuition in 2011?