Year	Percent
1990	22.75707
1991	21.87169
1992	21.60101
1993	21.41067
1994	21.49566
1995	22.20614
1996	21.20214
2004	22.19002
2005	21.34806
2006	23.18702
2010	21.77905
2011	23.02285
2012	23.23333
2013	23.64554
2014	24.61781
2015	25.48247