Year	%
2001	20.77
2005	20.18
2007	20.07
2008	20.01
2009	19.94
2010	19.52
2011	19.48
2012	19.46
2013	19.45
2014	19.41
2015	19.47
2016	19.51
2017	21.58
2018	21.91
2019	22.65
2020	21.56
2021	21.51