Year	% of total
1992	46.793951771653546
1993	36.712125215393456
1994	23.9107072135785
1995	25.161540362438217
1996	27.044125
1997	26.832640918580374
1998	24.587976878612718
1999	19.307877551020407
2000	19.127421758569298
2001	20.424458689458692
2002	22.727228412256267
2003	22.74767052767053
2004	24.55664524421594
2005	23.490317848410758
2006	23.435714285714287
2007	23.740896805896806
2008	24.97159509202454
2009	25.8705890052356
2010	26.199168674698797
2011	27.184107784431138
2012	25.632960687960686
2013	29.928440111420613
2014	28.2515953307393
2015	28.576995012468824
2016	30.27302211302211