Year	% of total
1990	36.12283274908155
1991	39.312872705057735
1992	38.14544653703574
1993	39.66648751222607
1994	39.64895626561757
1995	35.664606322447966
1996	37.168681853229145
1997	35.70026995553598
1998	36.92316196688862
1999	36.78820347549282
2000	37.59657919355207
2001	34.91388241064506
2002	37.330137949929586
2003	38.09285411934426
2004	39.08943799013704
2005	40.662487235996004
2006	39.906202718479655
2007	38.81010429122759
2008	39.23553719303367
2009	38.16933404854915
2010	39.14931278368547
2011	41.30790101450015
2012	41.129081842518765
2013	40.31811442531846
2014	40.42954307425983
2015	43.012105811445686
2016	43.84897575493582