Year	% of total
1992	36.98439594699922
1993	42.538281710914454
1994	45.561329904482
1995	46.70546648237733
1996	50.652086330935255
1997	50.42416401780038
1998	45.872987096774196
1999	49.92629107981221
2000	46.10231086657496
2001	45.372568270481146
2002	43.592880154639175
2003	44.70791180285344
2004	44.51285168682368
2005	44.72681104833647
2006	45.05621091354997
2007	44.27396319018405
2008	48.352104657849345
2009	46.728866709594335
2010	46.50433270082227
2011	46.600972663699935
2012	46.96757415952538
2013	45.988198630136985
2014	49.784328018223235
2015	49.19961275626424
2016	48.96353194544149
