Year	% of total
1991	54.322418469653954
1992	55.43126690105502
1993	58.7539802814282
1994	62.68107450072237
1995	63.218022407687016
1996	63.820236078663804
1997	64.07791842611759
1998	62.824488415293146
1999	61.752331612015276
2000	62.15209573674162
2001	66.80570478097569
2002	62.95989214273398
2003	63.58198053618091
2004	63.19754578353248
2005	63.083347917659914
2006	62.35730163798141
2007	62.88920727281242
2008	66.60771692029486
2009	66.96951433914666
2010	67.11416550263671
2011	66.4328206264673
2012	66.08277236384846
2013	66.7739522811244
2014	66.71909083206565