Year	%
1975	14.11966
2000	43.94104
2001	46.30221
2002	43.24397
2003	40.49151
2004	41.69406
2006	64.49324
2007	66.4301
2008	63.42877
2009	49.61741
2010	62.33976
2011	63.62904
2012	64.42043
2013	62.4557
2014	53.87652
2016	58.95045