Year	%
2000	3.83806885064808
2001	3.45948099364388
2002	3.51497612679359
2003	3.46441106223424
2004	3.325814211606
2005	2.97372222633333
2006	2.82628845889641
2007	2.74731370230527
2008	2.77802451913442
2009	2.68471838693133
2010	2.46620532784756
2011	2.41374444661866
2012	2.21239330729457
2013	2.12022644652535
2014	2.17945825879704
2015	2.24490786102929
2016	2.08996118467348
2017	1.83825714121972
2018	1.83905525302935
2019	1.73344582483235
2020	1.70895201351863