Year	Percent
1988	31.08504
1989	32.8
1990	32.66355
1991	35.27676
1992	37.26507
1993	39.10583
1994	38.36445
1995	40.68169
1996	46.31762
1997	41.18761
1998	36.05528
1999	34.88163
2000	34.18771
2001	34.541
2002	34.4048
2003	33.62225
2004	29.90445
2005	28.48328
2006	28.68029
2007	26.88021
2008	23.48553
2009	18.76074
2010	17.44826
2011	16.56532
2012	16.6542
2013	14.63787
2014	14.71866
2015	14.06076
2016	12.83447
2017	12.51458
2018	11.67529
2019	10.3739
2020	12.16966
2021	12.41223
2022	10.93595