Over ten years
Public university tuition has really, really increased as state support has dwindled. MSN Money lists the top 100 institutions with the largest increases. My alma mater is number 100. The University of Tennessee is number 14. Lots of Illinois, Georgia, North Carolina, and Florida institutions on the list.
#100. WESTERN ILLINOIS UNIVERSITY
Percent in-state tuition increase (2005-2015): 61.5%
Percent out-of-state tuition increase (2005-2015): 57.26%
Tuition and fees (2015-2016): $12,889.00
Tuition and fees (2005-2006): $7,980.66
Total enrollment (2015): 11,094