Year	Percent
1991	28.253
1992	28.613
1993	28.786
1994	28.526
1995	29.577
1996	28.751
1997	29.114
1998	29.246
1999	29.307
2000	29.162
2001	29.573
2002	29.536
2003	28.592
2004	29.194
2005	28.759
2006	29.182
2007	29.294
2008	29.67
2009	30.171
2010	29.832
2011	32.216
2012	29.87
2013	29.849
2014	29.805
2015	29.688
2016	29.194
2017	29.475
2018	31.338
2019	31.891
2020	31.439
2021	31.159
2022	30.934