Year	Percent
1989	15.60209
1990	15.46104
1991	13.7719
1992	7.26336
1993	7.5572
1994	6.10956
1995	6.69223
1996	6.54938
1997	5.86976
1998	5.10339
1999	6.58065
2000	5.75172
2001	5.87572
2002	5.56571
2003	5.50295
2004	4.90444
2005	4.25592
2006	3.86131
2007	3.7789
2008	3.75334
2009	4.08445
2010	3.3439
2011	3.15073
2012	2.92603
2013	2.9936
2014	3.36061
2015	3.8731
2016	3.84022
2017	3.55363
2018	3.39425
2019	3.5303
2020	4.00635
2021	3.87
2022	3.90142