Year	% of total
1990	71.18316845300482
1991	72.3224510137944
1992	66.89994935249256
1993	73.64610130543902
1994	76.1188327321939
1995	75.57570945467033
1996	71.52497564681006
1997	70.8089217745301
1998	68.79446763945468
1999	72.86817294999943
2000	70.95863030551303
2001	64.94469995072798
2002	62.38639442730388
2003	64.30931724829516
2004	65.33037989928917
2005	63.79841948237775
2006	64.65822125616468
2007	64.80369622680223
2008	64.53424963205912
2009	65.3989819236067
2010	60.57840253728044
2011	59.915062927312896
2012	56.92460436287066
2013	54.09423723633737
2014	55.012093342066834
2015	52.75510159126866
2016	53.63946377890546