Year	Percent
1991	51.172
1992	52.166
1993	49.653
1994	49.194
1995	47.843
1996	47.846
1997	45.107
1998	52.803
1999	65.167
2000	54.523
2001	42.565
2002	30.153
2003	24.532
2004	17.394
2005	13.461
2006	9.627
2007	7.107
2008	4.877
2009	5.125
2010	5.825
2011	5.672
2012	5.551
2013	5.485
2014	5.221
2015	4.917
2016	4.608
2017	4.477
2018	4.334
2019	4.277
2020	4.149
2021	3.989
2022	3.829