Year	% of total
1990	2.549842404483446
1991	2.6153409376486567
1992	2.1687721923946377
1993	2.35343068573554
1994	2.3633285104128454
1995	2.177100187852579
1996	2.4607407359588898
1997	2.2154162106827906
1998	2.5393242298921916
1999	2.408346245950919
2000	2.6121816889695544
2001	2.636164764253412
2002	2.743432529278865
2003	2.642643949471703
2004	2.521427266844711
2005	2.5307495265962525
2006	2.465842501144376
2007	2.4665145055375466
2008	2.2394005301509528
2009	1.8312682322577831
2010	2.003726080770659
2011	1.6425019944155281
2012	1.4787096298785651
2013	1.4518096578529214
2014	1.6796943448140236
2015	1.775871236266423
2016	1.6215221113748168