Year	% of total
1990	31.438026474127557
1991	40.92841956059532
1992	32.42044861763171
1993	24.694189602446485
1994	23.806306306306308
1995	23.72455390801709
1996	37.364043506078055
1997	32.1127385707945
1998	23.80541659479041
1999	31.94647201946472
2000	29.859767891682786
2001	32.68691588785047
2002	36.528301886792455
2003	40.62893081761006
2004	31.840477713798247
2005	30.411740725642073
2006	43.038233490083826
2007	40.72521483965625
2008	39.09745923397801
2009	36.1465254085114
2010	45.14863437452845
2011	49.5077125041024
2012	33.37116912599319
2013	43.05041069415365
2014	45.45808208519743
2015	49.82830290981384