| 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | |
| 44.2 | 39.9 | 39.7 | 47.3 | 55.6 | 54.3 | 53.0 | 53.7 | 53.5 | 54.7 | 56.2 | 53.4 | 60.1 | 58.0 | 59.9 | 58.4 | 54.7 | 37.6 | 30.6 | 35.0 | 35.6 | 14.1 | 59.4 | 61.7 | 65.1 | 61.8 | 48.5 | 66.8 | 68.4 | 49.6 | 63.9 | 64.2 | 65.2 | |
| 22.8 | 14.2 | 13.2 | 27.7 | 26.6 | 27.5 | 35.9 | 35.7 | 35.7 | 32.7 | 27.3 | 24.4 | 20.9 | 22.5 | 19.9 | 23.4 | 20.2 | 12.1 | 8.9 | 13.1 | 11.3 | 32.3 | 12.1 | 20.1 | 21.1 | 23.6 | 44.1 | 21.6 | 19.5 | 15.6 | 21.3 | 20.9 | 18.5 | |
| 33.0 | 45.9 | 47.1 | 25.0 | 17.8 | 18.2 | 11.1 | 10.6 | 10.8 | 12.6 | 16.5 | 22.2 | 19.0 | 19.5 | 20.2 | 18.2 | 25.1 | 50.3 | 60.5 | 51.9 | 53.1 | 53.6 | 28.5 | 18.2 | 13.8 | 14.5 | 7.4 | 11.6 | 12.1 | 34.8 | 14.7 | 14.8 | 16.3 |