2007 5.1
2008 4.9
2009 5.5
2010 5.3
2011 5.7
2012 6.5
2013 7.0
2014 6.1
2015 5.5
2016 5.3
2017 5.0
2018 5.5
2019 4.6
2020 4.0
2021 4.7
2022 3.8
2023 2.2
