Year	% of total
1992	34.02236269664486
1993	36.89399162861491
1994	39.40831837755912
1995	39.28580864120225
1996	49.294879951460516
1997	46.28295811119573
1998	44.05521872676129
1999	48.3463958394662
2000	47.95781962472258
2001	47.46419364498419
2002	43.07403895505692
2003	44.772867395451655
2004	49.34941004102363
2005	50.7168406621306
2006	42.67973518865752
2007	40.2319734734414
2008	40.14679255301496
2009	37.0508133497166
2010	46.96089809248126
2011	37.84697869638826
2012	35.54195679613401
2013	33.64329151154132
2014	32.23768486174824
2015	31.273341017446427
2016	29.137389813664598