Year	% of total
1990	60.302522931113366
1991	64.11557626748578
1992	68.06528579970836
1993	63.357772952387236
1994	61.34840362777196
1995	59.48026803249888
1996	53.52980362180192
1997	53.92864539380411
1998	63.35186078765338
1999	69.75231755720668
2000	66.28203165733166
2001	69.36709704169697
2002	72.16577477101329
2003	78.48922818962437
2004	71.02167713766906
2005	64.93164985890108
2006	63.66704678556095
2007	57.55907777267403
2008	63.96641666284277
2009	63.87512672605908
2010	66.81051954908608
2011	67.03086288324333
2012	64.69679572230362
2013	64.20997582730443
2014	63.56961914082146
2015	61.26102808391741
2016	63.638683765384094