Year	%
1983	22.6
1987	22
1990	24.5
1993	22.8
1999	21.8
2004	23.7
2005	23.4
2006	24.7
2007	24.1
2008	23.7
2009	22.4
2010	22.4
2011	22.6
2012	22.5
2013	22.8
2014	23.3
2015	23
2016	22.9
2017	23.3
2018	23
2019	23.9
2020	21.6
2021	21.4