Year	Percent
1982	22.23643
1983	24.64461
1984	22.45763
1985	22.94003
1986	25.41118
1987	25.03055
1988	25.34802
1989	24.77617
1990	22.99207
1991	27.84226
1992	32.26213
1993	32.21409
1994	32.2146
1995	26.51454
1996	19.76877
1997	18.83085
1998	16.13689
1999	15.97394
2000	10.46201
2001	9.30772
2002	9.95478
2003	13.72045
2004	16.15756
2005	25.68131
2006	33.71191
2007	36.74601
2008	30.5639
2009	18.60183
2010	13.30276
2011	13.82416
2012	14.7008
2013	14.05679
2014	19.61499
2015	25.12472
2016	21.66508
2017	18.47704