Year	% of total
1990	2.549842404483446
1991	2.6153409376486567
1992	2.1687721923946373
1993	2.3534306857355394
1994	2.363328510412845
1995	2.1771001878525786
1996	2.4607407359588893
1997	2.21541621068279
1998	2.539324229892191
1999	2.40834624595092
2000	2.6121816889695544
2001	2.6361647642534125
2002	2.7434325292788646
2003	2.642643949471703
2004	2.521427266844711
2005	2.5307495265962525
2006	2.465842501144377
2007	2.466514505537546
2008	2.2394005301509523
2009	1.8312682322577831
2010	2.0037260807706594
2011	1.6425019944155281
2012	1.478709629878565
2013	1.4518096578529214
2014	1.6796943448140242
2015	1.775871236266423
2016	1.6215221113748164
