Year	Percent
1989	20.60074
1990	22.44919
1991	28.1126
1992	25.37548
1993	24.46199
1994	31.16995
1995	26.86195
1996	19.31366
1997	20.58723
1998	27.33931
1999	10.90939
2000	7.57206
2001	5.30555
2002	7.09924
2003	8.44988
2004	7.02232
2005	26.46166
2006	16.47123
2007	5.93549
2008	15.93845
2009	9.26297
2010	9.24639
2011	11.54635
2012	10.74194
2013	7.6742
2014	5.03746
2015	6.55352
2016	6.15688
2017	5.07162