Year	% of total
1993	99
2001	99.6
2004	98
2005	97.9
2006	98.3
2007	98.1
2008	98
2009	97.9
2010	97.5
2011	96.2
2012	97.1
2013	98.3
2014	98.3
2015	97.7
2016	97.4
2017	98
2018	98.1
2019	97.6
2020	98.2