Year	Percent
1999	29.84029
2000	29.36324
2001	28.8625
2002	29.15814
2003	34.04443
2004	34.12079
2005	33.5032
2006	33.65915
2007	35.08139
2008	35.88992
2009	38.81115
2010	37.19037
2011	36.29446
2012	35.35143
2013	35.07266
2014	34.62634