Year	Percent
1990	17.16245
1991	30.24777
1992	29.93852
1993	38.21358
1994	29.1869
1995	41.95835
1996	47.43301
1997	45.09748
1998	47.16241
1999	37.16457
2000	34.02992
2001	34.99547
2002	37.72931
2003	37.94363
2004	35.46419
2005	35.87647
2006	40.81762
2007	43.21999
2008	43.40776
2009	39.74623
2010	34.39056
2011	32.71904
2012	36.49792
2013	30.15215
2014	28.35296
2015	24.75028
2016	29.95104