Year	Percent
1991	28.749
1992	28.284
1993	26.51
1994	23.632
1995	22.508
1996	22.362
1997	22.485
1998	23.653
1999	24.615
2000	25.565
2001	19.128
2002	19.894
2003	18.627
2004	19.961
2005	21.274
2006	23.949
2007	23.113
2008	22.246
2009	21.311
2010	19.902
2011	21.403
2012	22.945
2013	24.461
2014	24.347
2015	24.228
2016	24.042
2017	24.044
2018	24.014
2019	24.029
2020	24.02
2021	23.992
2022	23.946