Year	Percent
1990	20.07347
1991	17.73353
1992	18.28416
1993	19.8644
1994	20.59601
1995	19.72715
1996	22.46318
1997	23.7232
1998	20.48029
1999	21.78817
2000	18.97596
2001	24.69645
2002	21.01325
2014	18.02696
2015	16.02773
2016	13.50435