Year | |
---|---|
2001 | 15.1 |
2002 | 15.7 |
2003 | 16.9 |
2004 | 18.6 |
2005 | 19.8 |
2006 | 18.1 |
2007 | 19.7 |
2008 | 19.4 |
2009 | 17.5 |
2010 | 18.4 |
2011 | 16.7 |
2012 | 16.8 |
2013 | 18.4 |
2014 | 18.0 |
2015 | 19.4 |
2016 | 16.3 |
2017 | 16.5 |
2018 | 14.7 |
2019 | 15.9 |
2020 | 14.4 |
2021 | 14.2 |
2022 | 14.3 |
2023 | 13.9 |
2024 | 12.7 |