Year	% of total
1990	71.27504039493692
1991	69.50208357555026
1992	72.09984456219645
1993	73.48132994672883
1994	71.73326247160496
1995	72.87552557405054
1996	73.96249703719667
1997	74.28475383728482
1998	73.50536815263153
1999	74.16533385090753
2000	70.13821350811448
2001	70.39380714786905
2002	69.86246616850464
2003	69.74644078624812
2004	69.29592991535421
2005	68.57141995307265
2006	69.47994319835227
2007	69.28048986762988
2008	69.50734523744282
2009	67.4233935026758
2010	66.67921435641195
2011	64.93527415967405
2012	65.08201899686176
2013	63.74931631204765
2014	59.66320668167828
2015	61.11419948689205