Year	% of total
1992	31.95576675849403
1993	29.903511904761903
1994	59.01996350364963
1995	74.5936752136752
1996	79.47544747081712
1997	80.25679640718563
1998	80.52605187319884
1999	73.22209003215434
2000	72.10393258426967
2001	72.62697222222222
2002	64.29003205128205
2003	63.70102857142857
2004	65.83045212765957
2005	68.73569506726457
2006	69.9915144766147
2007	72.35273076923076
2008	72.50219683655536
2009	70.33159645232816
2010	68.10142857142857
2011	76.08653846153847
2012	79.87905594405595
2013	80.4073090909091
2014	81.36992700729927
2015	70.66185393258426
2016	82.67023668639054