Score 2007[4] 2008[5] 2009[6] 2010[7] 2011[8] 2012[9] 2013[10]
5 15.3% 18.4% 18.0% 17.1% 17.0% 16.4% 18.9%
4 18.0% 17.5% 17.9% 18.5% 18.4% 19.3% 21.5%
3 23.0% 20.0% 20.2% 19.3% 19.5% 20.1% 18.8%
2 18.5% 14.3% 14.2% 12.7% 14.6% 15.0% 14.9%
1 25.3% 29.9% 29.8% 32.3% 30.4% 29.2% 26.0%
Mean 2.79 2.80 2.80 2.76 2.77 2.79 2.92
Number of Students 97,136 100,586 104,789 115,077 122,651 132,425 140,006