| 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 | |
| 33.4 | 47.6 | 47.9 | 16.0 | 16.8 | 12.4 | 7.0 | 11.4 | 13.2 | 11.4 | 20.7 | 22.8 | 12.7 | 11.6 | 15.6 | 13.9 | 17.4 | 51.0 | 56.8 | 37.6 | 46.7 | 61.1 | 21.3 | 10.7 | 9.1 | 15.6 | 11.9 | 5.6 | 8.1 | 23.3 | 9.7 | 9.6 | 12.9 | |
| 25.4 | 16.2 | 15.8 | 43.7 | 38.5 | 36.6 | 47.8 | 43.0 | 41.5 | 43.0 | 32.6 | 30.0 | 30.2 | 31.2 | 29.6 | 32.8 | 33.3 | 17.1 | 9.1 | 16.9 | 11.8 | 20.5 | 20.0 | 24.7 | 24.5 | 19.4 | 20.5 | 22.2 | 22.5 | 26.0 | 29.2 | 31.8 | 30.9 | |
| 41.2 | 36.2 | 36.3 | 40.3 | 44.7 | 51.2 | 45.2 | 45.6 | 45.3 | 45.6 | 46.7 | 47.2 | 57.1 | 57.2 | 54.8 | 53.3 | 49.2 | 32.0 | 34.1 | 45.5 | 41.5 | 18.5 | 58.8 | 64.6 | 66.4 | 65.0 | 67.6 | 72.2 | 69.4 | 50.7 | 61.1 | 58.6 | 56.1 |