Year	%
1998	7.859416757569161
1999	6.4279391414566485
2000	4.791994635211365
2001	3.5953649288664993
2002	6.857358383440975
2003	4.82848514104953
2004	4.226819911048532
2005	5.649290731258564
2006	5.33767953021314
2007	3.1295910766826633
2008	6.035776610856883
2009	3.9125461952757097
2010	3.0010407989808803
2011	3.553409306431826
2012	6.024904932875875
2013	1.317234332822342
2014	5.2975701178144625
2015	4.256988940379995
2016	2.54895980164814
2017	1.1031666620408662