Year	Percent
1987	20.76302
1988	20.04219
1989	22.26351
1990	24.46707
1991	24.64883
1992	20.85198
1993	21.54067
1994	14.5724
1995	13.76976
1996	12.22905
1997	12.5154
1998	12.06807
1999	11.87501
2000	13.95179
2001	13.97609
2002	12.60325
2003	10.49954
2004	10.43704
2005	8.87531
2006	7.23906
2007	6.283
2008	6.5354
2009	6.9054
2010	7.40221
2011	8.15022
2012	7.76131
2013	8.69231
2014	10.15461
2015	12.05938
2016	11.7257
2017	10.17766
2018	10.13953
2019	8.96518
2020	9.31015
2021	10.88577
2022	8.22221