Year	% of total
1990	6.92499805337743
1995	6.80922525200367
2000	7.15245820414738
2005	7.10689325856134
2010	7.0568925386604
2011	7.04641736316018
2012	7.03575567386748
2013	7.02488959529378
2014	7.01381961959856
2015	0
2016	0
2017	0